oh to remind you of something.... if you play with multiple homeworlds, losing just one of them means defeat... so fortifying your last homeworld is useless (at least, that's what I've heard).
And you really need some easier settings lol. Gravity drill could work in your advantage, but cluster bomber is trouble. Both easier types would be best. put golems and spirecraft on easy, you do NOT want exo's on 10/10. turn Core Shield Generators (ship type) off in a snake map, that will be your doom, even in a 7/7 game. and the Ai plots need to be off... all of them. especially the hybrids.
Do all this and you might be able to capture... at least 3 planets.... lol. 10/10 wave type AI's are supposed to be unbeatable, even with easy settings. If you manage to beat 10/10 the way you are playing now, then you are the master of AI War.