Surprise in the mail

So...I haven't really touched on it, but I have a very bad thyroid.  I was having heart palpitations right after I turned 30 and I started freaking out.  I didn't know what was going on.  I went to the doctor, and he couldn't figure it out.  I was perfectly healthy.  (NOT overweight at the time)  So, he ran a thorough bloodwork on me, and lo and behold I ended up having this outrageous thyroid issue.  Never even had a clue. My doctor said it was the worst case he has ever seen.  WHAT??   Since starting the meds, 8 years ago, I have gained 70 lbs.  I am a hot mess.  Today, in the mail, I receive a letter from my doctor stating  my cholesterol is bad now too :(  Great.  Also my vitamin D is low...but he says that is in part due to us living in Cleveland.  A lot of dreary days with no sun.  So, they are giving me a prescription for Vitamin D and want my bloodwork redone again.  Needles.  I used to hate them...now they are a part of my life.  Feels like every three months for the past 8 years I have been stuck by needles.  And, I have small veins.  And, now that I am fatter, it is even harder to find those suckers.  I hate getting bloodwork done.  I have wanted to see an endocrinologist for a while now.  I have to get a reference from my doctor.  I just don't understand how a healthy woman goes from only having mild heart palpitations to  a hot mess, WHILE ON THE MEDS.  My weight is an ongoing battle.  My lack of motivation is another thing all together.  I haven't told anyone in my family, but I do believe I am going crazy.  I know that the thyroid can create bad things chemically in your brain.  Schizophrenia.  Alzheimers.  etc.  I feel like I can't remember anything anymore.  Even simple things.  I forget where stuff is all the time.  I forget things I said two minutes ago.  I forget things I have done.  I was NOT like this a short while ago...and it kind of scares me.  I laugh it off with my family and friends, but it really does bother me.