Just need advice. What would you do?

I started this job about 2.5 months ago. I’m currently going to school for my bachelors. I make pretty decent money here, I like my schedule for the most part but suddenly things have been sucking as far as the culture. At first everything was great. Everyone was nice, helpful, appreciative, inclusive. Now they all go out to lunch with out me, they keep scolding me on things that I wasn’t taught to do or asked to do, they will tell me to do something then try to correct me and say they told me to do something else. It doesn’t make any sense. One time someone complimented me infeont of everyone(president and all) and then one of the people I’ve been having this common problem with chimes in and says “why aren’t you doing this?” And I said “well I was told not to” and the person that told me not to, didn’t even speak up and was standing right there. Idk it’s a really high stress job while I take full time classes... but I need to pay the bills. It’s just so awkward being in an environment where I feel everyone is against me. Everyone even gets annoyed when I ask questions. At first it was the exact opposite. It’s hard to convey my feelings on here but I just feel so out of place, every day drags on. But it’s also a great job and good experience :(