Please help I keep messing up

Well my boyfriend broke up with me last week because he was really overwhelmed with anxiety and had a lot going on. Hes gone through a lot all this life and doesnt always handle his stress and anxiety well. I talked to his girl best friend about it and she said he loves me and wants a relationship with me hes just going through a lot and needs space so Ive been giving him space. Well yesterday to get my feelings out I wrote him a letter that no one was supposed to see. My friend who just went through a toxic break up advised me to do it. So I meant to send it to her showing her but I accidentally posted it and deleted it as soon as I noticed. I talked to his best friend last night and she said he saw and it made him feel really bad. She has before advised me to give him space and not Try and talk to him however I messaged him last night because I felt awful and wanted to clear everything up with the accidental post and he told his friend and shes upset that I didnt do as she suggested and that I mentioned her and I feel awful. I dont know what to do. I keep messing up. I tried to fix a misunderstanding but ended up creating another one and I feel so bad.