I too am hypothyroid as well as being diagnosed with Hashimoto's Disease. ED is definitely a sympton of hypothyroidism as well as the weight fluctuation. Are you currently on any type of thyroid replacement? If not, this may help. I have not been on it long enough to tell if it's going to help my ED - hopeful though.
Best of luck man!
I suffer from sexual performance anxiety too and I know how you feel. I am always able to attain a good erection, but just before penetration I sometimes lose it. You are young and healthy, so I'm sure things will improve with time. If the situation persists, you could try oral drugs. I'm currently taking Cialis 20 mg and a yohimbe supplement. I'm also taking oral phentolamine (brand names Vasomax, Vigamed), which is very useful in these cases: phentolamine blocks the effects of stress hormones and promotes blood flow to the penis. Vigamed is not available in the US but you can buy it on the Internet. For example: www.onlinegenerictabs.com Good luck!