Why people want to punch me and how to defend myself?

How to have a voice? It’s so weird that literally everywhere I go people want to tread on me for no reason at all. I’m always a chill dude, friendly, energic, try to make everyone feel good, most of all I respect everyone’s boundaries and never ever lay a finger on anyone, I don’t even joke about that, but still now and then what I get is just people trying to put me down, literally trying to punch me/hurt me physicaly or making me feel bad or try to start a fight, argument, debates or confrontation with me for no reason at all. Why I’m always seen as the punchbag anywhere I go? I mean, it’s not possible it’s just a coincidence, I’m a magnet of assholes, it seems like the universe conspires agaisn’t me…

I mean:

\> In school people used to joke about me, my teeth, let me down, and when they wanted to do some stupid punch joke/slap game kids do, I was the main target. I used to be much more violent when I was a kid so I got into lots of fight, luckly the school principals were supportive and never mistrusted me, always siding with me, sending warning to bully’s parents and getting them expelled, but it never stopped people from doing that. I changed class, skipped years, etc, doesn’t matter, anything I did to escape and meet nice people was in vain.

\> Around the same time, I used to have english classes, and I got expelled because a dude was bullying me so hard I broke a flower pot onto his head… at swimming classes and theater classes physical bullying was there too

\> At college, the same fucking thing happens, out of the blue I’m riding the elevator with a classmate, then he just punchs me in the belly, no reason, then I ask in pain why, he just say “idk, I just felt like punching you, sorry”, no matter how many times I sit down with them to talk (they do and apologize, but keep doing), tell my principals, or even punch them back, they NEVER SEEM TO STOP.

\> Yesterday I was with my girlfriend helping cost-free our college theater and the other stagehand acted like assholes to us, like if we didn’t knew our job and tried to slap me in the neck, I mean, people who never saw me before did the same thing…

\> Finally, last week me and girlfriend went to the movies with 3 friend of ours, this college girl, her sister and her boyfriend also from college. We are waiting for a cab outside the mall, like, 1:00am, talking in a circle, then out of the blue her sister went towards me for no reason at ALL and punches me in the belly. I agonized in pain on the ground and no one said nothing, no one did nothing, in a few minutes their cab reached, they went home like nothing happened, even hugged me goodbye on the ground, and I stood there with my girlfriend sat down on the sidewalk without understanding why, WHY????? The next day she sent me an audio on whatsapp saying the exact same fucking thing: “Hey, sorry for yesterday, idk why but I just felt like punching you, sorry about that”. WHY?

WHY? WHY PEOPLE ACT LIKE THAT? Who they think they are? More… who they think I am? And still, no matter how I stand up or what I do, it never stops, it never ends, I feel hopeless man… It’s humiliating my gf seeing me this way… I was talking to her yesterday so f\* angry and she said she doesn’t know why people act so gratuitous jerks towards me, and I mean, it’s only ME. WHY ME? WHY THEY CHOOSE ME TO DO ALL THIS SHIT? I’m tired but wherever I seem to go this gratuitous persecution seems to follow me, and for no reason at all. If I was an annoying person or that doesn’t respect boundaries, I’d understand, but I mean, I don’t see any reason for people acting like that to me, but they just act… Why?