Struggling to Connect with Others

I’ve finally realized that I’m just so lonely. I’ve got walls higher than Everest but I know that with time I could let people in. Like I desperately want close friends but I just can’t find anyone who I connect with or who will stick around. I’ve gotten so scared to get close to people because I’m scared they will abandon me or because they just wind up being people who want to take advantage. One of which has happened every time I’ve tried. Those I could see myself getting close to always disappear before I’m ever able to take a single brick off my wall, even when I explain up front that it takes a veryyyy long time for me to open my self up emotionally and they say they understand. Does anyone else know this feeling?