Hi confused -
Welcome to BPDR. I'm glad you found us.
Unfortunately we can't really tell you if you have BPD or not, as we aren't mental health professionals and it would be unethical for anybody here to diagnose you. The best thing for you to do would be to see a psychiatrist to talk over your problems, though I know that in the UK it's often a difficult and prolonged process to get that referral and that must be very frustrating.
Anger, irritability, and rapidly changing moods can certainly be part of BPD, but there is generally more to it as well. Have you checked out the DSM-IV criteria (found
here)? You're supposed to have at least 5 of the 9 criteria for diagnosis -- those who have less are just considered to have "traits." There's other good information on the main page, too -- you can get there, if you haven't already, by clicking on the way top left of the page where it says "happy, healthy living" and "bpdrecovery.com."
Also check out our "tools" in the box on the left. A lot of us use them to help sort things out when our thoughts or actions take us astray. For instance, you could use the "Ten Forms of Twisted Thinking" to figure out some ways that unhealthy thought processes might be leading to your anger response, and then "untwist" them. And you can use The Five Steps to come up with alternative ways to deal with problems that frustrate you, that maybe would be more effective than an outburst of anger.
Feel welcome to stick around and read in the different forums -- maybe you'll find some situations that ring some bells with you and give you some insight into what's going on.
Good luck -- I hope we'll "see" more of you here.