This will likely help: http://health.shaunagordon.com/so-you-have-pcos.html

As for your questions:

Where to start? I recommend starting with diet. I responded to another post recently with my usual guidelines. They've helped several women that I know of and probably many I don't know about: http://community.myfitnesspal.com/en/discussion/comment/31870341/#Comment_31870341

The metabolic doctor might give you meds, it depends on what your test results look like. The most common medications prescribed are Metformin (an insulin sensitizer), Spironolactone (a diuretic and blood pressure medication that's known to reduce androgens), hormonal birth control (much to my dismay, as unless it's something like Yaz, it just covers up the problems), and progesterone supplements. Your gyno may suggest Clomid and other fertility treatments, but like the birth control, it only masks the real issues. Some doctors will also prescribe supplements like Vitex (chasteberry; a general hormone balancer), Inositol (B8, has the effect of increasing insulin sensitivity and improving egg quality), or others, though these supplements are generally only utilized by naturopaths or doctors in Europe (however, you can get these things over the counter without a prescription, just make sure you inform your doctor). Many of these things can help you lose weight by correcting the underlying hormone issues, but keep in mind that none of these are "weight loss" drugs, nor should you be put on weight loss drugs without exhausting methods to correct the underlying hormonal issues (especially since you appear to be physically able to lose weight, but lose motivation too easily).

You feel like crying, because you don't know what to do, you're frustrated, and it feels hopeless. It's not hopeless. You know you're fertile, you have a child already. You just need to get your body back into a state where it can make use of that fertility again. Starting with a good, whole-foods-based, reduced carbohydrate (especially refined) diet will very likely get you most of the way there. Additionally, your cortisol may be one of the hormones that's elevated for you (if you also feel anxious, on edge, and snippy, then cortisol may be the problem; it's worth checking out Phosphatidylserine, a supplement that is known for reducing cortisol). PCOS affects the entire endocrine system, as well, so your thyroid and adrenals may also be affected. Your doctor should run a full thyroid panel to ensure you don't have a co-morbid thyroid disorder.

Your opportunity to have another child is not being taken away from you, but you do need to take action now, or things will just get harder as time goes on. Make the conscious decision to improve your way of life, so that you can improve your quality of life. Make that decision today, and every day. Wallowing for weeks on end over a stall in weight will get you nowhere, and sure as hell won't get you any closer to your goal. Stop looking at only your weight, and look at your health, because your weight will continue to be a fight if your body is not healthy.

Arm yourself with knowledge. Read through the archives in this group, there's a ton of stuff here. Then, go read through every PCOS resource you can get your hands on. Two common ones to start with are http://paleoforwomen.com/pcos-an-introduction/ and http://pcosdiva.com/ (note: both pretty heavily promote their book, diet plans, etc., which require you to pay; you don't need them to learn about PCOS and create a way of eating that works for you). Create a list of questions for your doctor appointment and write them down (take that list with you). Unfortunately, most doctors are pretty clueless or have severely outdated knowledge of PCOS, so it's important to be informed and be an advocate for yourself.

I suffered two miscarriages in between my first and second child. Yes, second child . I am finally at a healthy BMI, I am over the not so pleasant side effects of Metformin, and my periods are regular for the first time in my life. It is hard, but not hopeless! Best wishes as you figure out your plan of action.