Sorry I haven't read the entire thread. I'm so sorry about the terrible experience of your dh's death. I lost my dh suddenly and traumatically almost 4 years ago now.
I have to say that your 'drinking and partying' doesn't sound very unusual or extreme to me. The night before my husband's funeral i put out a distress call to pretty much everyone I knew that I did not want to be alone, and I had 30 people rammed into my house chatting and drinking. That's what it was like for some time - I wanted the healing company of my friends and family and that didn't involve sitting with a cup of tea wearing black, I wanted full blooded life. I'm sure some people judged me but I didn't give a crap then and I don't now. Of course there were quiet times with ds but he was a child - he jumped into and out of grief and needed his own friends and not to have to support me.
My sex life was another thing- just to say that I started sex dating within a year of my dh's death because I was unable to cope any other way. It may have been a dysfunctional coping strategy but as dysfunctional coping strategies go, it was one of the most enjoyable. I'm now seeing a nice man and ds has met him, though I am going very slowly on that front - he certainly won't be moving in any time soon.
Try not to hear your mother's words as judgement- from what you're saying she is just telling you how she feels about her own situation. Before dh died I would have said the same, that I wouldn't have bothered with another relationship, because all LTRs are hard, especially when your partner is ill and needs you very much. But when it actually came to it, my wishes were completely different. Why not just ask your mum a bit more about what she means?
Yes I would spend time talking to your kids, especially the eldest, and I wouldn't rush to integrate your worlds too quickly. But you're not doing anything wrong.
WAY was no good for me im afraid - I found that nobody seemed to be grieving the way I was. I have a friend who lost her husband very young 12 years ago and she still considers herself married, in love with her husband etc. That seems to be more common in WAY. Its not wrong either.