Welcome Ashley,
I work full time and I have to say I have a pretty sympathetic boss. We are a small company, so we are all close to each other(most of us). I have always liked my job, so making adjustments while being at work was mandatory for me to keep working full time. At times I want to cut my hours back and then other times I can push right through the week. The stress of my job can vary everyday. So when the stress is high....I have to admit I take a day off to regroup a little and rest all day. When the stress is low, like this time of year, it is easier to get through the day.
Taking one day at a time is the best I can do. I have made accomodations at my desk area, like heating pad, fan and I have the best chair I could get for my desk and I can dress as casual as I want(lucky for me). I also take two breaks a day, one for 30 min and the other 40 min. (we have a small couch in the lunch room, in which I use ALL the time) at times when I know that no one is in there, except maybe my dh.(yeah, my husband works at the same place)
I wish you all the best, I know it is soooo frustratiing not knowing what to do, keep checking out this site and check on some older posts to help find some other suggestions and some fun and encouraging conversations.
((Hugs)))