Um, this is a very easy mission. I don't think you suck, though, I think you are doing something wrong. If I read you right, you are having trouble destroying the 25% you need. Between all the stationary cargo ships sitting around and the Rzr/F fighters, you should be able to get your kills in no time. Why are you attacking the station? There is no point to that.
Take out the first wave of Rzr/F fighters, and then hit the Enkidu. Next, finish off the fighters. After that, all you have to do is beat up on the containers.