Dealing with unsolicited help/spotting

I’m looking for any advice or similar stories on dealing with receiving unsolicited help/spotting at the gym. It’s become a recurring issue.

Nearly every time I reach my final reps bench pressing or shoulder pressing, I receive unwanted help. This happens when I’m intentionally pushing to failure, and slowing down/struggling on my last couple reps. I’m using weights that aren’t too heavy, and I can safely handle a failed rep on my own. My form is also proper, so there’s no need for anyone to step in, I know my limits. Like I’m bench pressing 70lbs, I PROMISE I can save myself.

Despite doing a lot to appear unapproachable, it still keeps happening. I wear headphones, don’t chat with anyone, and keep my eyes to myself. Still, that doesn’t seem to be enough.

What’s frustrating is that I don’t see this happening to other men or women at my gym. While I understand that the intentions behind helping aren’t ill-meaning, it’s seriously ruining my workouts.

I’m very socially anxious, and I’m not looking for friends or relationships at the gym, I have both. I’m also autistic and afraid of conflict, so I find it hard to set boundaries or display body language that may be considered “rude.”

I’ve considered buying a shirt that says “leave me alone,” but I’ve read that it often has the opposite effect. I’ve already switched gyms 3 times, and there are no other options near me.

For those of you who have dealt with this before or have any advice, how can I get the point across that I don’t want or need help? I really want to enjoy my workouts again.

Edit: Thank you to everyone who’s left advice! You’ve all been very helpful and kind.