Hi and Welcome to Psych Central! I was Dx w/ Bpd 3 yrs. ago too.
The impulsivity is incredible, isn't it!! I started therapy for it back then.
A few suggestions that may help you, I hope: if shopping sprees are a problem - cut up every credit card, if you MUST have 1 For Emergency situations, give it only to someone you trust & is responsible.
Delete all e-mail that involves stores, all postal mail - throw away catalogues, sale ads, don't even read them, recognize them & toss. Mail carrier may be able to help you out w/ junk mail.
Junk food - Don't buy it! None, not I deserve it, I had a tough week, no. Write Lists before you shop - Buy only what's on the List.

Urges?? Distractions!! In PTSD forum there is a list of coping skills=fun distracting things to do!! I've collected some if you need more! LOL! Go & have some fun!!!

PM me anytime!!Thinking of You,
Holmes

P.S. All decisions (except answering this post, LOL) I think about for 24 hrs. and only take action after 48 hrs.