Still can't do it reliably but the fact that I can operate it at all now gives me some hope. I have a nice blister welling up on my thumb from trying to work the slide release. Then I realized I can put my left thumb on top of my right one and push with the left one instead and that works much better.
Back to building up the strength.
Perhaps this is more gun than you can handle. Education, practice and repetition will help but it sounds like you are really struggling. I think you should look at other guns. CornerCat my help point you in the right direction.
If I were you I would take my time and look at lots of guns and get some training.
I'm glad you've made the decision to arm yourself...good luck.