I understand what you are saying DuDu...been there...done that.
Missing your old friends from whom you've been seperated from for one reason or another, is a natural thing but it doesn't mean you've made a wrong choice or that JW's are the "true religion" or that you've actually even really missed out on anything. Chances are, if you'd have been there, you'd have had a nice time but likely it would have been the same old same old. Either way these events are over, they've moved on so have you, no sense looking at the past with regrets when there's no need to.
It's easy to look at the past or at other peoples lives or even their photos and see them through rose colored glasses. Hopefully you're not making yourself feel badly by projecting romantic notions onto these things. If you had spent your life as a non JW but moved away from your old town or neighborhood you'd be having much the same feelings. The hard part about it as a former JW is that so much of this sadness is so unndecssary and so uncalled for.
But as you said, your life these last 3 years has been wonderful and that's what counts the most !