Is this a mental illness?

I know I might be being silly but this is kind of getting out of hand for me and I want to dig deeper as to why I behave this way. Is there some sort of mental classification/illness/disorder about this:
I feel like I always have to occupy my mind with a specific person. I find a small thing, like making eye contact once 🙄, to force myself to have a "crush" on someone but this crush lasts for at least a year. I get so occupied that I spend my free time almost researching them, and it can't really be a real crush since it's not based on me knowing them truly. It also affects my mood. Sometimes I realise that it's not a reality and I'll never be with this person and I almost go into a sort of depression mode. It's so overexaggerate and I'm only starting to realise how ridiculous these behaviours are. I get over the person for like a week and then find someone new to obsess over.
Has anyone else felt like this? Is this actually normal and do people feel this way over random "crushes"? Can anyone help me get over these antics??

I used to be like this but you have to differentiate between platonic and romantic , realise that you have higher standards than if somebody gives you one compliment and romanticising them off that . Realising that this one thing or few things is the bare minimum and that you deserve more than that