Struggling with Depression: Rollercoaster of Emotions

I don’t know what the heck is wrong with me. I spent all week feeling awful, just depressed and down and I couldn’t figure out why. Then yesterday morning and early afternoon I actually felt like myself for once, I felt happy and I was in a good mood. Then just before my shift ended it all came crashing down. I got depressed, my boyfriend came to see me which we had planned all week, and instead of being excited to see him like I normally am, I didn’t want to see him at all, I didn’t want to be near him or anything (which I think stemmed from something else), and then I was just irritable and just way out of it for a while, then spent the rest of the day feeling absolutely depressed. 😔 I was so happy when I was feeling good. It felt nice to feel upbeat again 🥺 idk what the heck happened 🥺 depression absolutely sucks 😔