Synthroid and pain in the neck

i've been on synthroid for 9 years. started at some low dose and gradually went up to112 mg. get extreme itching all day everyday if i don't take allegra for that.not a rash just itching. that doesn't bother me as much as the fatique. every joint in my body aches all the time. sure there are better days but fo rthe most part it's bad. tried physical therapy and chiripratic care but no avail. they ended my sessions. my legs get sooo weak and my feet burn lower back really aches. sometimes muscle cramps. i'm very negative towards my loving family and it hurts me to do so. can't seem to keep upbeat. soo tired all the time.
is it the syntroid? i used to be very energenic and a doer. now i have spurts of activity in the morning , but then i just can't get motivated. help me any suggestions?

I've only been taking synthroid for a little over 2 months and not only has my husband noticed behavioral changes with me but I feel them as well. If I didn't know what depression felt like, I would say that would be the problem, however; it's a lot more than that. I've felt "sad", as though my heart were breaking and then I get angry and have the "I don't care" attitude. Mood swings galore which is very unlike me. I'm naturally a very outgoing and friendly person who has turned to the irate, don't bother me person who likes to be alone. Though these changes have taken place, I feel they may just be temporary which is why I will remain on the med. It's truly a pain in the neck to experience such changes and not be able to so to speak "control" them on your own, but in the long run, if it means being healthier and losing the weight that needs to be lost (on me), then for me, it's worth it. Thank God my husband understands all this!!!