I still have my Mother and have always been very close to her. When my Dad died we had some unresolved issue between us--not bad ones but issue non the less. The most important thing in life it to love your parent--even when sometimes I hear people say it is impossible for them to do so....even if in small ways to open the lines somewhat of communication--so when they are gone you can say I tried--I did my best...very painful scars latter if not dealt with in the here and now.Even if they rejext you to know you tried.
As far as Mothers Day I think they should have one for us single parents--who have to be both a mother and a father!!