Don’t know what to do....

Things at work lately have been really crappy. I feel like I can’t talk properly to my mentor at times even though out of work she is like a friend. Don’t feel like my manager can help either. I had a week off annual leave and it’s been great but I’m anxious about going back Monday. I don’t wanna tell my bf about the crap I feel from being at work. Don’t know who to turn to as people at work don’t seem to understand and I don’t wanna spill to anyone as it’s my problem not theirs and I don’t want to ruin the end of a wonderful week I have had away from work. I really don’t want to go back Monday but I got no choice. I do suffer from anxiety and depression but don’t know where to turn and what to do and who to talk to.