I used to be like that but mine stems back from when my ex used to beat me. I was scared of what he was going to do and had P/A hyperventilated and kicked my legs , waved my arms , flailed around and screamed as much as I could to keep him away from me. So even when I wasn't with him anymore my panic attacks put my brain in mind of protecting me so I would still lash out even if no-one was trying to hurt me (if you get what I mean?). I don't do this anymore as I realise I am not going to get hurt - I know there is no reason for my fear so I try and deal with it best I can. When I think that I have upset someone that I love I go for myself - will not say how as there is no need - and feel unworthy , suicidal etc... and I think that stems from abuse aswell , I used to get told that I wasn't good enough etc.... and thats ingrained in my head now - I feel apologetic all the time when I needn't be ,I feel smaller than everyone else.
Well I hope this answers your question , think I might have let a little more out than I intended about me but I'm gonna post this anyway.