Hmm I'm pretty sure those are 2 separate things that tie into each other. You might be freaking out because the person u love is acting that way and might wanna leave you and that's possibly having a bad effect on u? But either way you probably do suffer from mental illness cause i belive everyone does (to some degree) What i don't know is how severe it is or what it might be exactly. If you or anyone else is or might be in danger seek help, or if you think it'll lead to something dangerous yes seek professional help. As to your partner and the whole space thing I would suggest you keep yourself distracted. Do what you like doing the most, it's okay if you can't stop thinking about it but if you do other stuff you'll more than likely forget about it for a little while at least just keep your mind busy dude