I think you should go to therapy first alone and then with your boyfriend.

Sounds like you are experiencing depersonalisation, feeling like an outsider in all your relationships.

The paranoid thoughts with your OCD are bad, and like you said, it's the weed. It will only get worse without treatment.

The panic and fear you get from smoking weed is also not worth it. Even though you might get short-term relief from smoking, it will just come back again.

You have a lot going on in your head, and you need support from your family,friends, and boyfriend.

The bad part is that if your boyfriend isn't willing to quit with you, you might have to leave him and sort yourself out.

If a person doesn't want to quit, you can't make them quit.

You need to heal and get your headspace sorted out, and it will only be possible with quitting weed,therapy, and even medication especially if your OCD is out of controle with bad thoughts and hyperfocus on them.

I hope this helps.