Hashimotos postpartum

My TSH was tested throughout pregnancy and fell within the normal range. About a month postpartum I started gaining weight rapidly which couldn’t be explained along with other symptoms but just attributed it all to PP hormones as the doctor said was normal. I suffered with low energy, dizziness, unstable blood sugar, inability to lose weight, etc for 6 months until my next check up where my TSH ended up being 42 and by that point I felt like my brain wasn’t working anymore. Finally got medication and TSH down to 3 within 6 weeks but still feel incredibly tired, can’t lose any weight, have muscle pains all the time although my brain is working a bit better. Anyone have similar experiences postpartum? Did your condition stabilize? Any advice?