To me - it sounds like you have a lot of unresolved TRUST ISSUES from your past (possible childhood) and instead of healing from them you are transferring these wounds back into every adult relationship you have ever had.

When the new man in your life does something (consciously or unconsciously) that hurts you - your wounded soul automatically jumps into over drive with all the under lining issues your true self still holds inside....... and when this is done the SO will never have a fighting chance.

Ask Your Self

what can you do to help ease these wounded feelings?
who is it that broke my TRUST in the first place?
what can you do to stop the resonation?