> I have done all of that, except tried different ships. I only played with the starting ship, on hard difficulty, because I wanted to finish the main game before trying the extra modes.

You are playing on hard mode without any experience in handling game strategies and events, this is why you are losing. Try it on the easy mode and get a feel for some different strategies and ships. This game is not difficult, with some experience you can beat most runs in the game with any ship on the hard difficult.