"I was your only chance"

I'm 21 now... and that's on the last things my only relationship ever said to me back in Freshman year of high-school when I was 15. They were right. I've tried. I've tried my hand in person. Always get hit with "You're too sweet for me, I'd hurt you." I've tried online dating for a couple years now, and, even with a fully filled out profile and the best pictures I can manage when I decide I have a burst of confidence, I have gotten maybe 3 matches that actually respond. They actually texted first which is nice. It's usually "heyyy" but I can work with that. They bounce one response back and then are done... I don't know what I'm expected to do. I feel like a circus monkey. I avoid people that look really busy in their profiles or if they really like traveling because I can't match that energy. I just swipe on people that have at home hobbies/prefer staying in and aren't fitness people. I get likes every once in a while, but it's from people that I would literally have to be a caretaker for... I feel like a POS for turning them down because it's not their fault, but I can't do that to myself. It feels like it's all karma for being dumb and inexperienced 6 years ago, and I guess it gets worse everytime I'm shallow about the people that show interest in me.