I know this sounds bad, but after years, I'm beginning to feel angry at my mom for being so condescending. This is the way she's always been since day one. In fact, I've never met her approval, but I was always forgiving and have never held it against her.

But now, after my failed marriage and after having friends who have grown up in healthy households and who have been able to get over such things (due to their healthy loving parental upbringing) I'm beginning to think that the reason why I'm so repressed, unable to get over things quickly, and at times have such low self esteem is because I have never met my mother's approval.

I know that this is the case - I don't want to bore anyone with details, but lets say I didn't grow up in the most functional family.

But the question is, how do I get rid of that resentment? I don't feel like talking to her about it, as I'm sure she's going to take a sarcastic approach to the whole thing, and it'll make me angrier.

I sort of have the same problem.
My mother wasn't condescending but she wa passive aggressive and she had this thing about age and respecting your elders to a point of being indignant if she didn't like my opinion.
For a few years I had to ration my time seeing her to keep my sanity. Like I found that if I only spent so many hours a month with her we got along better. When I spent a lot of time with her sure enough things were going to crop up that had me agitated at her.

The other important thing is that you have to make your own identity and be your own person. Cut the apron strings of 'what they made you' and come to terms with who you are and who and where you want to be.

I know I still struggle with getting anywhere in my life because of some power the past seems to have over me but I don't let it get me down.

Also try to find the good qualities in your mom and look at her from a different perspective. Like I know this is how she is and how am I going to deal with it in a constructive way.

I know it is hard to tell moms the problems you have with them because they do become indignant and haughty that their daughter could talk to them about their short comings like 'who are you to disrespect your elders'

Dude, no matter what you went through, and where you came from, if you're an adult, you have the ability to define yourself, and its really not responsible to blame your past on how you act in the present.

Its up to you to choose what your about now. Be happy with who you are, and appreciate what you had to overcome to be able to love who you are now.