I feel your pain. I've had so many people and so many instances similar. The people who are truly your friends and have your best interests at heart WILL stick there for you. Those who don't are probably better off out of your life anyway. It's really hard especially when you think you've given everything and you feel alone. But trust me, everything happens for a reason and the best thing to try to do is to think on the positives and invest your time, energy, and love into something else. Something like a new friend or a pet or even a project.

different circumstances but I developed a similar mindset with friends and eventually family. so I’ve been here and…please don’t isolate yourself. please don’t pull away from people, it only makes things worse. it’s unbearable and it eats away at you. we can’t help needing or wanting people, you’ll only be denying yourself basic human connection. in my case, social anxiety took over my life and I spent years isolating myself from people. truly, it only heightens everything you’re feeling. I get what it’s like to hate yourself, trust me. I don’t know how things happened the way they did with your friend. but I get how it feels to value and trust only to have it fall apart. you deserve to connect with others and you deserve friendship. keep fighting.