Have you had anything stressful or traumatic happen lately? Sometimes with trauma and dissociation you can have times where it feels like nothing is wrong, and then be triggered into things again by a stressful time. I didn't remember any trauma from my childhood, until I had a niece turn the age I was when I'd been abused, and within six months learned about many parts, as I'd begun switching so often as a result of the reminder. I'd been diagnosed with a lot of different mental health issues (wrongly, in my case) to explain away behaviour that were a result of the trauma I'd experienced and pushed down.

You don't sound crazy at all, just like you're going through a tough time. It sounds like you've got a really supportive boyfriend, which is great.

If you can remember what big events were happening when you started noticing the major changes, and which conversation topics, places, situations, etc. Are happening when you switch (your bf may be better at that part, if you trust him to help you) it could help you figure out how to manage things, and would really help when explaining it to a professional to get help for it. The more details and consistencies you and your friends/family can come up with, the easier it will be to work through it.

Are there any adults in your life you can trust with this information? It's a lot for just you and your bf to be dealing with. A favourite teacher, guidance counselor or guardian perhaps? Good luck with things!!