I'm 28, and I really do understand. I was an unbelievably healthy person until last year. I began feeling really tired all the time, and having severe anxiety. My entire body ached all the time and I was having hot flashes??? My periods were extremely heavy with clots all the time. I had pnuemonia 2x in 6 months. I began gaining weight with the same diet. I had a car accident and a nodule was discovered on my thyroid. I gained 80lbs in 5 months. I have changed doctors 5x and I am now happy with the efforts of an internal medicine doctor I just started seeing. It has been a long road, and I have been in the hospital more than out for so many different illnesses I thought I was a hypocondriact (however you spell that). He is slowly peeling away at the problems and fixing them instead of just medicating them, and I am starting to get answers. It is scary but your thyroid has alot of control and effects over your entire body, and no matter how crazy they look at you or you might feel sometimes - don't give up until your better. God Bless and I will pray for you.
Just a comment - when I was about your age (I'm in my 50s now), I walked into my doc's office complaining primarily of depression and some of the things you say above. Prior to that day I was an upbeat, energetic, healthy young mother. My family doc said to me and I quote "You look terrible (nice comment don't cha think) and It could be one or more of seven different things so we'll test for them all.". Anemia will also produce many of the symptoms you are having - trust your doc and if you don't - find a different one. Ultimately I was hypo but I was also quite anemic. Make sure you are eating a healthy diet and not trying to diet too hard...gout is rather unsual in a young person (who isn't eating a wierd diet). A bad diet can wack out your immune system and make you prone to common colds, etc. Somethimes it takes awhile to piece things together and figure out what's going on and there might not be one magic diagnosis...it could be a combination of things. Find a doc you trust to systematically figure it out. Hopefully, too, you tapered off the Prednisone....and Prednisone can cause weight gain....not tapering off steroids can cause many of your symptoms....just some thoughts for you....
Difficult to give feedback without thyroid labs, but to test for thyroid dysfunction would look at TSH, Free T4 and possibly thyroid antibodies. An ultrasound is appropriate to determine if the neck swelling is truly thyroid. If any of this is not normal, would consider endocrine evaluation.
Also I have ALL OF THESE SYMPTOMS at one point or another EACH WEEK:
Severe fatigue, loss of energy, persistent sleepiness (I can sleep an entire day and still fell fatigued)
Weight gain, difficulty losing weight (I excercise 5 days a week by walking, to no avail)
Depressed mood (Taking Zoloft 50 mg a day)
Joint and muscle pain (Gout, knees hurt to walk, muscles feel weak)
Dry skin (EVEN WITH OILS/LOTIONS, brittle nails and hair, thinning hair (falling out)
Irregular periods (lasts a month, then nothing for 2 months)
Other symptoms include intolerance to cold, fuzzy thinking or difficulty concentrating, loss of libido, and puffiness in the face or extremities. ALL OF THE ABOVE...