Hello, i deal with the same issue lol and I've read somewhere that it's might be because of the following reasons, first emotionally unavailable or poor parenting, second fear of vulnerability because of early traumatic events, low self esteem, it's like it proves the point that we aren't lovable so them ignoring us doesn't disturb us but if they show slightest interest it contradicts our belief so it causes discomfort, addiction to rejection( yes this is a thing lol) getting used to chaos, we seek connection to sooth the loneliness but connection triggers discomfort. I hope this helped a bit. It all starts with knowing the means.