Ever Feel Like You Don't Belong???

I went to work today and after work....not a long day but, I worked without a break cause the day was just like that. After work I wanted to stay with my Manager just a little while some thing needed to be done....But I wasn't allowed to stay cause I was apparently going to be a distraction even though I was just going to sit and not say anything. I'm not sure what exactly happened but, I felt sooooo "put aside" and soooooo left out for some reason. I started getting frustrated and shortly after I was done work we were headed out for some staff dinner and at that point, I really didn't want to go just cause I felt as though I just don't belong. I should have listened to my heart. I shouldn't have gone cause I feel worse and I feel as though I'm at my job to just do the work, instead of enjoying it as I always do. I feel as though I try to talk to my Manager these days but, I just get brushed aside and that's it. Kinda like, I'm just not supposed to belong any more. I'm good at what I do and I know in my heart that I am but, today I just feel as though I don't belong and I can't stop crying cause I'm soooooooooo FRUSTRATED cause no one will listen and I feel like....I feel so used and I just don't know HOW I'M SUPPOSED TO BE so that I don't feel hurt next time and I can go into work, just do my job (even though I enjoy it) and just leave. I wonder, has EVERYTHING CHANGED without me knowing???? IS IT JUST ME????