Thyroid issues?

Hello everyone!!
  I am 61/2yrs post op.

Anyone have any Thyroid issues after gastric bypass?
Once a month for the last 3months i have been to the ER with heart palptiations
sever constipation  blah blah well all 3visits only one dr did a basic thyroid test and found
that i have Hypthyroidisim!!  added to all this i have gained like 17lbs and my diet has not changed!!    arrrggg Very depressed feeling like a falure

any words of understanding would be great

Thank  you in advance