Acting Without a Full Heart

There are times when I find myself doing something to help out someone else, but with a small twinge of regret. Not regret necessarily that what I am doing is not the right thing to do. I guess the regret is a bit about being a tiny bit jealous, or wishing to be in the same place as the person I am helping. It is also wanting to do this thing to help out, but knowing that the outcome of it could spawn results, some of which are good (mainly for the person I am helping), and some of which are not so good (the not so good results would be directed at me). I am beginning to learn that everything in life is double-edged. Sigh. What I wonder is, is it better that I am helping someone out despite my regret? Do I get more reward for it because I am not so enthusiastic? More credit for doing something that I am not so excited to do, yet I am doing it anyway because I know it is to the benefit of the other person? Even though I know that I might get hurt in the long-term. Or would it be better, would I get more reward for doing such an act with a full heart? I wish I was doing it with a full heart, because it would certainly be much easier that way. I once was talking with a friend about how hard it was for me to not shower and put on make-up on Shabbos. A lot of the other women at the shul I then attended did shower and put on make-up and looked so nice on Shabbos. I felt pale and yucky in comparison. It really was hard for me. But I cared enough about keeping Shabbos that I couldn't bring myself to break it in order to look a little nicer and feel better about myself. My friend told me how happy she was for me that it was so hard for me to keep Shabbos. She said the fact that it was so hard made it even greater that I was doing it. I wonder if doing this helpful act is the same - that because it is so hard for me and I am doing it anyway, gives it even more weight that I am doing it. Shows that I really do care that much about helping others, despite the regret and hardship that comes along with doing it. I wish I had a full heart to carry out this action, I feel like I should be happy about helping someone else. But maybe feeling the regret is okay as well.