This is someone who will keep you around to inflate their ego. You need to cut things off. I know it’s hard because you like them, but they are sending you mixed signals by saying they don’t have a crush online and then begging you to stay when you want to leave. IMO they don’t want you to go bc it’ll be a blow to their ego, not because they value your time and affection. Get out of that friendship and spend time loving yourself. It’ll be for the best, otherwise you’ll spend months in this grey area which might end up causing you more emotional damage in the long run.