How do i get over losing my friends?

Until I was about 25 I had a large group of friends, we all hung out together all the time as we all had similar interests. I then took a very stressful job and got involved in a relationship and both these things caused me to drift from the group. By the time I realised and tried to reconnect with them all they had 'moved on' and didn't seem to need or want me as part of the group anymore. I have just gotten on with things in the last couple of years and have a couple of other 'friends' although they are more just people I know rather than do anything socially with . Anyway I'm 29 now and after years of feeling lonely its now got unbearable. I have had years without things I used to enjoy like the pub at the weekend as I dont have anyone to go with and now its dawned on me I'm unlikely to have that again. I'm so low and upset and struggling for 2 months now I would say its the major thought in my head for about 85% of every day - I'm obsessed with wanting to turn the clock back. I think if all the group had drifted now that we are older I could cope but they all still hang together. Because of safety in numbers I guess none of them really notice my absense but even after 4 years I am still struggling to cope with being left out in the cold alone. I'm heartbroken every time I hear from mutual acquaintances of summer barbeques and hen nights and realise that I never get invited to anything like that and I could never throw a party like that either cos I have no one to invite. It's too late now to have a second stab at trying to patch things up with them - they would probably think I was a crazy stalker or a sad case if I admit to them I have not gotten over this or managed to make any other close friends after 4 years. The worst part is that I am actually a generally really social person - I cope fairly well in social situations and I am capable of making people laugh so please dont think I'm this self absorbed misery and thats why people dont want to know me. Also I dont need depression meds as its this one issue I have to deal with. I know all the advice about trying to meet new people - I have tried it and have got invited to a candle party as a result which was kind but not my scene -it was just my first invite to anything for so long that I was grateful for it so its nothing like getting to be part of a wee 'gang' with lots in common like I used to. What I'm looking for is some soundbites to help me try to lift the weight off my heart about the loss of my friends. Sometimes it feels like a bereavement. But its so hard to cope visualising them all out at the pub on a Saturday night or something laughing and having fun while I go round and watch telly with my parents. How do i get over the horrible heavy hearted feeling of loss for what I'll not have again and be able to wake up in the morning with something else of my mind instead of this??????