Hi sleepie,
I did not have a close relationship with my mother either although it was nothing similar to direct abuse or desertion. More like a very erratic mix of indifference and intrusiveness, and dyfunctional forms of "nurture" that led to many years of struggles into my mid-20's (with an eating disorder). And a life-long issue with trusting and being able to rely on women in any authority role (although this had improved a lot after my mid-30's). I don't have an issue making friends with women (well, more or less), but when it comes to authority, a very different plot. She was a very sad and troubled person in many ways, an abandoned child with abusive foster parents in her own childhood, and suffered from depression throughout her life, I think. Sadly, I did not care to get to know her this way before she passed away now almost 10 years ago -- I would handle her very differently now. I think she had an intense desperation for love and belonging but could never find it or create it within or in her relationships. Sad story. Basically what happened was that even I (her only child) detached myself from her at a very young age (4-5) and never let her close in any way, and pretty much ignored her when she was old and sick before her death (that was also the time when my alcoholism took off steep). I don't dwell on this much now but the long term effects are there and, I believe, will always be there with me. I also believe that this relationship with my mom contributed to a large extent to my never wanting kids/family when young, until recent years (the kids part failed though). I think I have accepted these things by now though and don't feel much resentment, although it's always interesting when my mom comes up in my therapy sessions, for example.
So in terms of playing a maternal role, the closest I got was supervising students, which I love immensely. One of my students had a similar experience with her mother to yours (based on your description), well actually both parents. She always feel quite uneasy around Mother's Day. What she plans to do this year is to do some volunteer work with children. She also has a therapist that is a sort of mother supplement for her (has been for almost 3 years now).
I definitely don't think it's self-pity to examine these things in our past, I do it myself quite heavily. What often helps me more though is finding some sort of "corrective experience" (like the students for me or what my student does) that goes beyond contemplation and examination. Obviously these are limited forms of substitution, but can sometimes be fulfilling.