Definitely try different races.
One (Thalians?) start with a PQ15 homeworld, IIRC.
Or, try making your own race. At least in DA, if you make your own race, you may end up playing against it later! I just won my first couple Suicidal DA games with a new race. Generally, I find the Yor to be the easiest to win with on highest difficulty settings, though I often tinker with the traits, homeworld, etc.
If you really, really only want to play as the human race, at least try different super abilities. Also, if you Control-N a few times, you can at least get "an Earth" with a morale bonus tile. Put the Political Capitol on that tile and your morale problems should be greatly reduced, if not eliminated. (Well, as long as you build no extra farms, etc there) Also, putting the Political Capitol on Earth lets you colonize Mars then trade it to enemy AIs and get it flipped back to you over and over again, which can be amusing.