Hi, Tess,
I am not a doctor or anything, but I do know that pregnancy in general can definitely affect your body permanently. With the difficulty losing weight, you may want to ask to have your thyroid checked. Apparently thyroid issues can also cause trouble with getting pregnant. I recently went to a fertility clinic, and they included a thyroid check in my first round of blood tests. I am not sure if it can also affect hair growth. It may be a place to start.
Good luck,
Jessica