People Who Have Experiences With Thyroid Problems after pregnancy, Help Plz?

Hey. i'm really frustrated. any one who has any experience with hypo or hyper thyroidism would be greatly appreciated. i never had a problem, until after i had my 2nd child. after i gave birth, the tested me, and said my thyroid function was low. my doctor said it could maybe just be because of the pregnancy, called post partum thyroidism. now, its been almost 6 months since i gave birth, and for the last 2 months my thyroid level function had returned to normal on the blood tests, but they checked it again this month, and now my thyroid is functioning over active. and that probably explains why lately i've been so sick, and tired and exhausted all the time. having chest and heart pains. just feeling so bad all the time. i don't know what i going on with me. thought my thyroid was just going back to normal, and now its over active. i'm worried about developing graves disease. my doctor is just going to check my levels again in another couple weeks and then decide what to do from there. what do you think. any one else have a problem with their thyroid like this after a pregnancy or something, and it kept fluctuating up and down. is there a chance, my thyroid might just eventually calm down and settle itself back to normal function without having to be on meds for my whole life.