Been there mate, I think everyone goes through at least one devastating break up during there lives, the only certainty you can be sure of is no matter how bad it seems right now it will get easier with time and hopefully you will look back and see the positive aspects of how having had the opportunity to journey with that person has enriched your life. Anesthetizing yourself with any substances will only prolong the pain and distort your perceptions, best to allow yourself to grieve the loss and process what comes up with clarity whilst seeking the support of those who care about you mate, I'd abstain from all drugs for a while if I were you. Too often in today's society there is an almost taboo about feeling and expressing extremes of emotion, just look at how many people are prescribed anti depressant medication by their doctors when they are feeling sadness, the only way to move through it is to feel it and process it, numbing it just buries it for a while only to resurface later. Go and seek out your friends and family mate, best medicine there is.