I find when I'm having intimate relations with someone I ejaculate quite fast in about 5 minutes or less is there any way I could help that.. its so embarrassing when it happens...

Seriously, how old are you ?

He was 18 last October.
Men have countless ways, but you have to work out what is best for you.
What many do is just have sex twice. That can be a treat for your partner, who gets lots of cuddling, stroking, and all kinds of tender and exciting foreplay while you wait to be able to have intercourse again.

Premature ejaculation is a very common problem. The Pause/Squeeze technique can be used. There are also drugs that help, such as Trazodone or Zoloft. For more info check out the link below.
Premature ejaculation Treatments and drugs - Diseases and Conditions - Mayo Clinic (http://www.mayoclinic.org/diseases-conditions/premature-ejaculation/basics/treatment/con-20031160)

Masterbate before hand (is that a pun or an oxymoron?). Anyway, it may help you slow down.

The best way to slow yourself down is focus on bringing your partner's pleasure, before you focus on your own. After giving her 15 quality minutes in other ways that SHE loves rather than you, your 5 minutes will seem will not be so disappointing to either of you. That means your full attention to what turns her on. In time this practice will give YOU greater experience and control over yourself, so take your time and learn your partner intimately. Even if you do get your 5 minutes first, what stops you from giving her more pleasure in other ways besides just humping away until you can sufficiently regroup?

Sex doesn't have to be over because you have reached your peak in 5 minutes, that can be just the beginning.