You just have to keep doing things to take your mind off of it. At the moment you aren't going to enjoy them. But if you keep doing it, eventually you'll smile for a minute, then two minutes and eventually you'll forget about her for the whole time and will enjoy yourself. You need to build yourself a new life without her in it, new experiences, new memories.
Nobody expects you to forget about her and move on in a matter of days, but you can definitely help yourself. Asking your Mum to show you photos is just utterly stupid though, it has no benefit except to hurt you. Try to remember that next time you want to ask. No good can come from it AT ALL.
I know what you're going through
@Jonnybmac - essentially where you are now is where I was a couple of years ago. It hurts, but it's not like any physical pain you've ever had.
ci_newman's post (quoted) is exactly right. It's critical that you deliberately do things that a) take your mind off your situation and b) if possible, for those things to be unconnected with activities you may have once done with your ex. Keep contact to an absolute minimum, or avoid it altogether if possible - I wasn't able to do this as much as I'd have liked, as we had to discuss what was happening with our jointly-owned house.
Reconnect with your family and friends. It's easy for these to take a back seat when you enthusiastically throw yourself into a flourishing relationship - I learnt recently that my own family always felt they were playing the proverbial 'second fiddle' to my wife's family ... that really hurt to find that out, as it wasn't intentional.
Use your time to explore new hobbies - in my case, going to the gym did wonders for my confidence and gave an outlet for the anger and frustration I was feeling. One of my family members still tells me to this day that it "saved your life", which when I thought about it, wasn't such an exaggeration. I'm now also taking up music again - I say 'again' as it was nearly 30 years ago that I last dabbled with writing my own.
What you are feeling is 100% natural and don't beat yourself up about it. If you feel the need to cry, don't feel ashamed about it - scream the bloody house down if it helps ... point is, don't bottle anything up, find a way of letting it out.
This last point might be a little contentious in light of the ill-judged rant I posted the other day (posted in anger and which I regret), but don't ever feel like less of a person because you haven't got a girlfriend - I don't know how old you are, but I'll assume between 20-30 for the sake of argument - there is so much more to life. The relationship of mine that ended a couple of years ago began when I was in my early 20s and with hindsight, it stopped me doing a lot of the mad stuff that most people do at that age. Hell, I only smoked weed for the first time last summer at the age of 49.
I'll be honest, at the age of 50 I've become so cynical about the whole relationships thing, I'm pretty close to being full-on MGTOW - please don't follow that example.