I have problems similar to this, but it's due to BPD. I become obsessed with specific people, which with BPD is referred to as a "favourite person", and I spend a lot of my time trying to interact with them, get attention from them, thinking about them, etc. I rely on their attention and approval to be in a good mood, and if their tone even seems off I become very upset (I internalize things though so I don't usually act too unhinged over it, thank God). I obviously idealize them a lot, too. It's much different than a crush, but the difference is hard to explain. It's a lot more intense, and is very dependent and unhealthy.
I recently have started to "get over" my current FP because I finally began to notice their flaws and how mean they actually kind of are to me. I've also forced myself to keep distance and keep interactions benign which has helped my obsession die down.