Hey there!
I hope you're doing alright. Thank you for sharing your experience with others here on the forums, this is very brave of you. I feel like in life you're always going to come across those people who are 'fake' friends and that's okay, people like that don't deserve you. You really start to realize which people are your real friends just by the way they treat you, the people that will stick with you no matter what.
I definitely know what it feels like having a fake friend. Cutting them out of your life is really the best thing you'll ever do. I remember that most of my other 'friends' started hanging out with that person more and they were all so popular at school. I do see them pretty often still because we go to the same school but you really just have to realize that you are so much more than that and you're way better off without those kinds of people in your life.
It's kind of strange how they never told you why they were avoiding you though, that's why, like
@UtopianistUnicorn mentioned before, it'd be a good idea to confront this person about the situation, if you haven't already. If that doesn't really end up working out, it's their loss because I'm sure there are tons of people just waiting to be your friend (me included). You really seem like a kind, reasonable person.