I dont want to be with my “bf”

Long story short I talked to this guy for about a month while I was in a different state (we live in the same place) because I thought we could be friends and when I recently got back he kept on pushing for us to meet even though my parents wouldn’t let him come over and he brought up the idea of him sneaking in. I live in the guesthouse so I said yes because I wanted to see if we would vibe in person. He came over and gifted me a grinder for magic herbs and a hoodie of his, I was kinda surprised at this because I thought it was too much for being just friends. Like 30 minutes in to hanging out he puts his arm around me and kisses me, I kissed him back because I thought I wasn’t gonna see him again after he left and then we made out. He asked if I would give him head and I said “why not” because again, I didn’t see a future with him. After that he left and he wouldn’t stop blowing my phone up every second of everyday. He called me his girlfriend and I didn’t know what to do because I never said I liked him and the only thing I think he could’ve misinterpreted me saying was me calling him funny. I don’t like him in a romantic way and now he’s sending me all these memes angled towards couples and he’s telling everyone him and I are dating... I don’t want this but I don’t know how to tell him, he seems unstable and I don’t want to hurt his feelings by “breaking up”(?)with him but I can’t date him. Any advice on what I should do???

UPDATE: uhh so I straight up told him I don’t want to be with him and I’m gonna block him on everything ,,, thanks for the help yall it rlly did help me. Much love thank u!!