learningtowalk,
I think its completely understandable that you would be thrown off balance by the exchange you describe. I think we have all been there and done that in some way shape or form. Its normal BPD stuff or as normal as BPD stuff gets.
I would suggest you don't worry about his text. Read it, don't read it, have a trusted friend read it, have a trusted friend delete it. In the long haul it doesn't matter. What matters is you. How you take care of yourself. What you do to bring good into your life.
This is what I have learned about engaging with my EX. No matter what the connection is that I have with her, sooner or later I end up hurt by it. And not a little hurt either. The pain we feel is all encompassing on some days.
I ran into my EX by accident at a public event twice in the last week. The first time it set me back quite a lot. The second time I was better with it. I guess I am still learning.
Letting go is a struggle. We are so bonded with our EX's it does some times feel like it's impossible. It's not though. It does get better. And it gets better in small increments. You are walking you way through the process.
You said in your post that you made the decision to turn the focus on to yourself. Excellent.
Now its like the old adage how do you get to Carnegie Hall? Practice Practice Practice . Every time your focus shifts to him, pull it back and substitute something positive for you in the future. Where you are going to be in 6 months. The new car you might have in 2 years. Anything. Replace the negative with a positive. Hard to do at first but it gets easier.
I also agree with BPDspell. Block his texts. If you can't block his texts, change his contact name to DO NOT READ. Do you really want to spend time trying to communicate with some one who just accused you of stalking? Not a good investment in you.
Be well.
babyducks