I feel that I have more than hypothyroidism, possible AF?

Hello,
I have been taking 50 mcg Levothyroxine for about a year.

Fast forward 2 years and I went to Doctor for checkup and my thyroid area has a few lumps, the doctor said I may need a sonogram.
I saw the lumps when I put on moisturizer, and it startled me as there are a few.

Why would this happen if my levels are considered normal now?

I feel that I have an issue with my adrenals, can the GP do a blood test for a possible problem?

My neck skin has dropped and sagged this year, it's crazy how my skin has thinned out all over too.
I feel lost, like I am just taking the Levothyroxine to cover up a issue, that is not being corrected.

Should I go to an endocrinologist, or is a GP able to handle this? I read here about treating the adrenal cortex first, how do I start?
Btw I am 44, taking Paxil, Levothyroxine and vitamins.