I was just diagnosed less than 2 years ago. I question it all of the time when I am stable though my episodes are very close together right now. Unfortunately it leads me to go off my meds and that ends very badly reminding me that it is real.
I once had a psychiatrist tell me I was making things up. That is very hard when things already seem so unreal. It made me wonder even more what was real and what wasnt. I told my new psychiatrist that sometimes I feel like I am just making things up and that he was right and she said that he never should have said that and she understood how invalidating that was.
Its real and it can have short breaks, long breaks, it can even feel like no breaks sometimes but it is all real. Take care