I know how you feel! I think an INFP experiencing their first relationship is like the most beautiful, generous, innocent, heartfelt and sincere thing in the world. It's truly a priceless gift. And sadly, the people we often end up giving it to are not worth it at all (our judgment of other people is not so great when we're naive... or too quick to fall in love). In a sense, our ideals get emotionally raped (sorry for the harsh description). No wonder you are bitter and jaded.
I was the same way after my first bf effectively ended the relationship by cheating on me. I was so angry I tried to turn into some variety of punk or goth, wearing only black and leather and dyeing my hair red. I grew out of that phase but the hard feelings of disappointment and deep underlying sense of mistrust and cynicism lingered. It's still there. My current SO is faithful and principled. He has given me no reason to mistrust him. Intellectually I know he would not hurt me. But I'm never "all in" now. It's too scary to have complete faith in someone. I come off to him sometimes as too paranoid or suspicious, but my walls of defense are on hair trigger alert at the slightest hint of something "off".
Unlike my previous self, if my current beau betrays me, I wouldn't think twice about leaving him in the dust. Like a porcelain vase that's been broken before, my heart would shatter easily at the existing fault lines and I'd be faster than ever at piecing it back together with hardly a tear. It just wouldn't hurt as much as it did that first time, when I couldn't even fathom that someone could break something so beautiful.
But... at the same time, it IS possible to fall quite deeply in love with someone new and trust them to a large degree (it might take a while to get to that point tho). This someone might actually value what you have together and handle the relationship thoughtfully and carefully. After enough observation, you'll see that this person deserves your whole love and your whole trust. I'm not quite there yet, but the fact that I'm hoping it will happen is a sign that my original, pure, INFP capacity to love isn't utterly destroyed. I hope that you too will start to see the light again, Thessaly. I'm sure what you have to give is much too amazing to be locked away inside. Just be more careful with it.