WITHOUT MY consent, a terrifyingly humorless stranger crept into my life and took over. The ground shifted beneath my feet, the mad bubble of felicity burst and I got into a right old lather.

She wore a black cloak. The better to be invisible, she tartly said. Forgetful, she was constantly leaving credit cards and purchases in store counters. She took umbrage at imagined slights: e-mails that were answered a day late, grammatical mistakes, inane chatter, slow service in restaurants, bad manners.

But she also raged over random cruelties, injustice, nuclear warheads, religious extremism, cancer – the kind that killed a beloved. Her rancor simmered. The rants became stridently loud. The rages fit to erupt. She drove me to tears, pillows were drenched from sweats and uncontrollable weeping in the night.

Full of prayer I would go to bed, but with hot flushes end in up in the shower in the middle of the night when sleep wouldn’t come. The hamster wheel of life was going round and round in my head. Worrying about my son going out bravely into the world without my guiding hand on his back; hoping I don’t end up in a home when decrepit, drooling and dribbling all over the place.

Lost in self-absorption

What if we all die tomorrow from a suicide bomb? Chemical peel or dermabrasion? Should John and I go out on a proper date, which will lead to... am I ready for that? Will I ever be ready? Is there an exercise for my wobbly bits? God! Gray hairs! Where did my waistline go? Should I start wearing firm-control panties the size of a small Balkan state?

She looked at me grimly, stoking the fires of my fears night after sleepless night. Lost in a dense fog of self-absorption, molehills became mountains and I was turning into a drama queen.

At 51, I was a workaholic jaded old cynic, fearful of losing my moorings, if not my marbles and going through the menopause. She was a stark, raving loon whom I hated, but also loved, for she was me and I was her, and I have the emotional scars and weight gain to show for it.

Life would be infinitely happier, said Mark Twain, if only we could be born at age 80 and gradually approach 18. It ain’t going to happen. These days, 50 is viewed as the great divide between the first and second halves of life. The point of anxiety and depression, when we look back and realize we haven’t achieved anything of great importance, but it’s unlikely we ever will.

Never going to be a boffo rocket scientist, work in the West Wing, carry Bill Gates’ bags, become a Nobel laureate, go topless in Cap-Ferrat.

A slight ache in the bone, the slant of shadows in the dying light of day as darkness gathers. Crazy hormones going completely awry. A menopausal woman cut off her husband’s penis because she suspected him of infidelity.

“I want to feel desirable again,” lamented a seriously depressed 49-year-old friend, who found her boytoy from an online dating site, and then flew into a murderous rage when he stole her iPod. Mark – all double chins, three bellies and love handles – dumped his wife of 30 years for a 20-year-old blonde. After six months of Viagra-fueled sex with babykins, he threw her out and wants his sweet wife – and old life – back.

A perimenopausal friend, getting ready to go out, asked her husband, “Does my bum look big in this?”

He, usually Solomonic in his wisdom, replied, “Just a little, maybe.” Post her tearful temper tantrum, he’s still paying off £30,000 of cosmetic procedures she has had done to herself.

Immutable rite of passage

It’s an immutable rite of passage: men and women cross the menopausal threshold, with little rebellions and acts of anarchy, running the whole gamut of emotional arpeggios, as if to affirm there’s still life left in these old bones.

It’s not easy, the body is no longer what it once was, and we are bombarded by an unrealistic culture of youth. Little by little I despaired. My moods swung high and low. Bye-bye collagen, estrogen and progesterone. I mourned – briefly – the babies I could no longer have. Suddenly, I irrefutably became middle-aged.

“Menopause is not an illness, just part of life’s many transitions,” my GP said, as he told me what symptoms to expect – vaginal dryness; irritability; anxiety; decline in sexual desire; anhedonia (inability to feel pleasure); as well as the risks – osteoporosis, cardiovascular problems. I said no to HRT.

“If you keep fit with exercise, eat and sleep well, alleviate the stress, not obsess about it too much, you will sail through it,” he added.

They never tell you how long it lasts. Age, said Tom Stoppard, is such a high price to pay for maturity. There’s a lot of help to be had. With advice from a nutritionist, an exercise regime, vitamin and herbal supplements, I hunkered down, to reclaim my sense of humor, perspective and proportion.

This being a journey, I was entering the next stage, with a new, different, lease on life and an opportunity to defy old age. Some women slip into invisible anonymity. Stop to shave/wax/ pluck; surrender to the slough of despond.

Real women, it’s said, don’t have hot flushes. They have power surges, and so others will experience what Margaret Mead called “postmenopausal zest,” a release of energy that propels them to take on causes, take control of their lives and embark on new challenges.

Well-groomed, assured, wiser and confident, they have the benefits of education and experience, and have access to cosmetic procedures, medical advances, mood enhancers and tight-control underwear.

How liberating it was learning to let go – anger and disappointments, the airbrushed images of beauty, soul-destroying ambitions, petty competitions for favor and recognition, buying useless stuff, displaying one’s possessions.

Counting, instead, the things for which I was truly grateful. Recalibrating my expectations. Ironing out some of life’s imperfections, and focusing on little pleasures – a walk in the park, books, writing letters. Lowering my sights to suit my reach. Accepting I will have good as well as bad days. Sometimes life pulls you up, sometimes pulls you down.

I’m no longer easily offended because I don’t take myself so seriously anymore, and no longer care – or not quite as much – what others think. Not so hard on myself anymore, I can judge myself and shortcomings more fairly, and accept what I have become. Perhaps life starts to get better, wrote Jim White, when we realize there’s no point trying to be something we no longer are.

This is the time of our lives, but also the time for resolutions, being kind, forgiving and the healing of wounds. I used to be a drama queen, but now ready for my next act, to face the music and dance.

Suggested reading list:

“The Change: Women, Aging & the Menopause,” by Germaine Greer ; “On Women Turning 50: Celebrating Midlife Discoveries,” by Cathleen Rountree; “Not for Wimps: Men and the Aging Game,” by John Parry; and “Passages: Predictable Crises of Adult Life,” by Gail Sheehy