Hi healing36,
Welcome to the family! I'm so glad that you found this site and I'm sure you'll gain lots of knowledge here that will help you. Have you taken a look at the lessons and insights? There are links above. You'll find some fantastic articles, including one that I refer to time and again - Surviving a break up with a person with BPD (link above the board). I found that learning helped me a great deal to understand what had happened in the relationship and what my ex's experience was like for him.
I think what I need support in is completely cutting him off. I still feel a lot of pain around the thought and also feel guilt about hurting him and further reaction, even though we've broken up etc.
When you say you want to completely cut him off, what is the reason? It might sound like a silly question but we all come at this from different perspectives, so whilst many of us have gone down the NC route, it is worth some thought before deciding if that is your best option. There is a really good article on this here:
https://bpdfamily.com/content/no-contact-right-way-wrong-way It helped me a lot to assess where I was coming at it from and be sure that it was the right thing for me.
Whatever you decide you are in the right place for support. Everyone on the Detaching board has been through a break up and there are many seasoned members who are testament to the fact that we can recover from this. Their wisdom is so valuable, whilst you'll feel comforted by the fact you're not alone in your feelings as many are in the same place too. The pain and guilt you describe are so difficult and I feel for you, having been there myself as most of the people on here have. It takes time and self compassion to maneuvre through this, and is sort of like a grieving process. What support do you have from family / friends? Sometimes it's hard to talk to others who know us about the experiences we've had as it doesn't necessarily make much sense to us at the time, but eventually things will start to become clearer. If you have people around who can cheerlead you it does help. I found this forum such a lifeline and I hope the same for you. It's a great place to get things off your chest and share your thoughts and feelings at a time like this.
Also, there's a small part of me that buys into things he says that are blaming and are about all the things I needed to do different and also when he says how much he loves me, etc.
After any relationship breakup there naturally comes a time to assess what went wrong, what our role was, etc. We have contributed to the relationship, after all, however try not to beat yourself up in the process. It's good to think about what you might do differently in future. We can all do that. Right now, it's more important to look after yourself and allow yourself to deal with the feelings you have, especially when it sounds like you have things left that you're tying up like the cat (not literally!). The rest can come in time. Blame often comes up and it can be too easy to take all the blame or cast all the blame after the demise of a relationship. Just remember two parties were involved and nobody is perfect!
Hearing that an ex partner loves you is a very painful thing in itself. Does it match his actions in your opinion? Some of my most difficult moments have been around this at the end of my relationship and I know how it can make you feel. It was somebody on here who pointed out that if the words don't match the actions then you have to go off the actions. That was hard for me to hear as his words still meant so much to me and I felt so strongly towards him that I really wanted to believe that the words were how he really felt, but I knew deep down that I was discounting his actions which were too real to be ignored.
Is he collecting the cat when you are not there? What did you agree upon? I can imagine that even if you're not going to be around it will be an emotional time for you and I hope you can immerse yourself in something that is positive for you and is self soothing in some way. Do let us know how you're getting on. We're here for you.
Love and light x