Im so sorry to hear your story.
From what I know, there is no "Cause" of PCOS. No "one" thing will trigger it. Its just one of those unfortunatly VERY common things.
Heres my story of PCOS, i might help a bit...
I started getting AF at 11 and my mum knew quite early on something wasnt quite right. It started with horrendously heavy periods, every month. I do not exaggerate when I tell you I needed a super tampon and maternity pads at the same time as a tampon would only last 30-45 minutes.
Mum took me to family planning who put me on the pill, this also helped with the acne that started around the same time as AF.
By 13 AF was still heavy but even with the pill was very irregular. I would have AF for months then nothing for months etc etc. By 15 years old I was sexually active and my mum didnt trust the pill was working so we tried Depo. Depo didnt work! and I fell pregnant! The PCOS was diagnosed once my full history was discussed with the Dr's and confirmed by ultrasound, I dont have cysts ON my ovaries, my ovaries are full of them.
Unfortunatly due to being on the Acne medication Roaccutane during the early pregnancy (obviously I didnt know) I was advised to terminate.
For the next 7 years I used contraception on/off hoping to control the PCOS symptoms and obviously avoid pregnancy. at 20 after 2 years of being with my partner I decided Id had enough of the emotional side effects of taking the pill and while I risked AF becoming out of control again (i used to "skip" it on the pill, only having it every 3 months due to the heavyness and the extreme pain) we decided to try an IUD as I had read online how it helped other woman.
While AF stayed very irregular with the IUD, it wasnt exeptionally heavy and the cramping was bareable. Anything was better than the pill that I felt made me go loopy lol.
I was 22 when we decided to try for a baby. Knowing my AF cycle was so irregular because of an-ovulation caused by the PCOS I was aware it would take time. I researched HEAPS on the net, read a tonne of other woman's stories and spoke to my gyny at Auckland Gynaecologists. We both agreed that weight loss is THE NUMBER ONE remedy for PCOS.
Now in saying that, its not easy, and the amount you have to lose might be drastic, in my case it took 14kg to regulate my cycle. Part of me thinks it was 50/50 weight loss and actual strenuous exercise that did it. A walk a few times a week wont do it I think, I worked my ASS off lol.
It took 7 months to get my cycle from 87 days to 33. The 6th cycle was 35 and I knew I had ovulated, the 7th was 33 and im semi certain I ovulated, the 8th I think would have been about 30 and I know I ovulated because we concieved!
Not everyone has such good luck as we did, I know I was extremely lucky. Even after losing 14kg I was still quite overweight, and I do blame alot of my weight issues on the PCOS.
Another down side of having PCOS is you are at a MUCH higher risk of developing gesational diabetes and sure enough I did. Its not the end of th world, just another little hurdle PCOS throws at you.
Feel free to PM me if you have any questions, im a PCOS pro haha. You might find if you talk to other woman inyour family (both your mum and dads side) that you will find a few woman with PCOS symptoms. Actually diagnonis is quite a new thing, and I discovered my aunt and grandmother on my dads side both had Gyny issues that were quite possibly PCOS related.
Sorry for the novel, just hoping to help. I know I felt a bit lost and unsure so I hope I can help in some way!