I think it's time I should let him know that I do not want to maintain any contact with him. So that he stops reaching out to me. He has habit of twisting meaning of sentences and has blamed me for poor communication in past. Hence I have want to take advice from folks here on how should I go about it. Also he has some personal pictures of mine which I tried to get a few times but he had some or the other excuse. I am ready to give up on that as my peace of mind is more important for me at the moment. I also didn't have high hopes to get them back.
NC is a tool for us to heal - not a punishment for them. I stress this because the "how" we let someone with an emotional illness that is rooted in abandonment should be taken seriously.
If you can let go of the pictures and be ok with it - perhaps this will give you some peace quicker. From my experience and many I have seen here, objects tend to be quite difficult emotionally to retrieve.
If you must say anything, keep it simple direct and about you.
"I understand this may be hard for you, but I am hurt, I need space from you to heal, I will contact you if/when I am emotionally ready to be friends."
SET - sympathy, empathy, truth
Don't expect him to react nicely - he will be hurt and angry and how that is displayed, well every BPD is different.
Don't justify or backtrack - be consistent so you are not sending him mixed messages.
I tend to be of the camp that goes with actions on this - don't respond immediately when he reaches out, send back 1 word, boring answers, eventually you no longer are a source of emotional support for the BPD and they let go. But if you have already done this or if it is too triggering for you - direct is best.
Peace,
SB