Don't give up! The first couple of years aren't always the best, especially in the soil out there.
You need the trees for the shade in your area, otherwise you would roast.
Have you tried different seeds maybe? Or could you plant some veggies in the front yard if there's more sun there? Mix them in with the flowers or plants?
There are lots of stables near you, perhaps you could add some old horse manure to your soil and that would help. I know it works for me here! lol (I have more horse manure than I know what to do with. We spread it on the fields when they aren't planted and the rest of the year we dump it at a landscapers place down the road and he mulches it. Otherwise we'd be overwhelmed.)