The push/pull cycle is something that I think almost of us around here have experienced and can relate to. It's hard, painful, and confusing to say the least. I'm glad that you found SWOE and this site. I know that we can provide you with support and help you as you work toward your future.
How are things going today? Has he come back from his trip?
There are also some very informative articles on this web site - if you click on the home tab it will direct you to the articles - they will give you some good advice on how to cope in a BPD relationship.
Keep writing. Tell us your story - it helps you to get it out and it helps others when they see that they are not the only ones suffering.