marjan, my T taught me the difference between "like" (what we feel for a friend and those we enjoy being with) and "love" and it made a lot of difference in how I viewed being with my stepmother. I loved her but didn't have to like her because I didn't get to choose her like I do my friends and intimates.
Think about a friend and ask yourself 3 things you like about that friend and then apply those 3 characteristics to your mum. They won't fit

No need to feel guilty; there are all sorts of people out there we don't want to be with and our mums just happen to be one. You're a wonderful daughter though because you take her out anyway (because you love her) and don't say anything about her bad behavior, etc. But there's no reason whatsoever to feel guilty! They're just not our friends!