Agree that you're not going to attempt intercourse for a while. That will take some pressure off (and if you have an erection while she's ready, you can ignore the agreement and go for it...)
During that time, have a read of Bernie Zilbergeld's books, 'Men & Sex' or 'The New Male Sexuality' - the latter is the second edition of the first, originally titled 'Male Sexuality', but there's no much difference. At least one person is usually offering one of them for 1p+postage on Amazon (it's M&S at the moment, I see...) It has a very good programme of exercises, alone and with a partner, for getting control over this.
My other thought is to wonder if you're actually sleeping together. If so, do you wake up with an erection?
And actually passed?