I've heard that hypo can cause weight loss (but it usually causes weight gain). Also, to my understanding, hypothyroidism doesn't always cause weight related symptoms and your low weight could be genetic. Some people are naturally very skinny. Do you have any relatives who are very skinny (and have always been this way)?
Has your doctor put you back on meds now?
Please post the results of the test he did to determine you were hypo. Include the reference ranges from your own lab report as they vary lab to lab.
How long have you been off meds?
Do you know the cause of your thyroid problem? Do you have Hashi's?
Also I'm always very very cold I feel like lately I can't think.. I used to be smart but literally lately I'm so slow and its like my brain just doesn't want to work even simple math like counting change takes forever... I've read that this can happen but I'm wondering is it serious?? I'm scared that since I've been off meds for so long I will never be normal again. I just don't know much about my disease... I guess its a disease..