I don't know what's going on!

I struggle with depression and anxiety but have been doing pretty well lately. suddenly today I started crying for no reason, like, nothing happened to provoke it or anything. after I had calmed down a little, my cat was walking by and I called her cause I wanted cuddles and she left (because she's a cat) and I started bawling because she walked away! I don't normally cry for no reason and I hate crying. any suggestions on what could be up??