I think this is finally it

I was diagnosed with Hashimoto’s as I had high levels of TPO antibodies back in 2020. My TSH was at a 7 when I got tested, but I had another test a few weeks later and it was down at 2. Couple of later I went to an endocrinologist and they tested it and it was up in range at a 3.5, so I went on a low dose (25mcg) of levothyroxine. A week later I started to not be able to sleep, felt nervous and anxious, and at a higher heart rate (up around 90-100). They told me I should stop taking it.

A few months later went to my PCP feeling off again and my TSH was about a 4. Decided to try Synthroid this time (25mcg) since I wasn’t feeling great then. Within a couple hours of taking it, I had the same symptoms — nervousness, anxiousness, very high heart rate for a few hours (110-120bpm). Stopped taking it then and haven’t touched it since. Both times my T4 levels were in normal ranges.

I’ve been feeling fine since then with what I think were some hyper/hypo episodes here and there. I’ve had some weight gain which I’m not sure has been my erratic thyroid hormones or what.

As of the past few weeks, though, I had some episodes of high heart rate for a bit in the beginning, and as of the past 2 weeks now, I have had chronic extreme fatigue and some additional weight gain.

I think this is it, though — I’m thinking I’ve finally hit full on hypothyroidism. I’m still waiting for blood tests to come back to confirm, but based on my previous history with levo, I’m a little nervous about the side effects of the medication if the blood work confirms my suspicion.

Did anyone else feel the same way starting out with meds? Are these symptoms normal? Could this be a different experience if I have lower T4 hormone in my bloodstream this round? I want to make sure I do this the correct way this time with starting on meds so I can get back to feeling normal.