I am also hypothyroid. Had my thyroid removed completely in 2008. I have also had problems with the medication. The gold standard for thyroid here in US is synthroid, but for some reason my body does not absorb it because I continued to be severely hypo even though the dr (endocronologist) said it was within range. I find that my range is a lot lower than the accepted standard in order for me to feel good/function properly. I finally got my gp to prescribe armour natural thyroid which is basically ground pig thyroids. It works for me beautifully. I got my life back. But I also have a difficult time getting the right dosage. I am assuming that it is because of constant change in my weight.
Hope you get yours straightened out. A lot of people don't understand how much not having good thyroid levels can impact your life and how much it affects weight gain/loss. Wishing you the best on your PS journey. I am so glad I don't have HMO. They seem so hard to deal with. Keep us informed on how it goes for you.