This is something that I have also struggled with most of my adult life. Way too many people have let me down. However, if it someone you are interested in having a relationship or a friendship with, be 1000% up front with them about your feelings and explain to them that you don't mean to push them away, but it is a coping mechanism that you have built for yourself and want to have them be the person to help you through it. If they care enough about you they will take the time to understand. You can choose what you tell them, you may choose to give them history when timing feels right, but make sure to let them ask questions, if you don't want to answer that question, you can just say, "I am not emotionally ready to answer that question right now, but I will tell you ....." Or something along those lines. It is always difficult to open up so much to someone, but not everyone is harmful, I promise. If they are willing to hear you out, they are most likely understanding.

I agree

It takes time

Two of my best friends in college dumped me as a friend because I was "a lot." That was 5 years ago, they are still best friends to this day. What I learned is to pick your head up and keep putting yourself out there. Make sure you're not putting all of your emotions on other people or dipping into toxic behaviors due to fear of being abandoned, but use apps like meetup.com to find friends with similar interests. Especially after college, I found wonderful friends. It takes a lot of vulnerability and you will get hurt or embarrassed on occasion. But you'll also meet lovely people who will love you.

i have the same problem, its definitely best to tell people that you do it and how so they know when you do it and know its not that you actually want them to leave, and always vheck in with them when youre feeling like you pushed to much, just because they dont message first anymore doesnt mean they wont respond in some of my experiences, though it depends on the person