Crackle,
I'm afraid you need to start again. Hire a rotovator, let that do most of the work. Then rake the soil as level as you can get it, and remove as many stones as possible. Once as level as you can manage walk up and down the soil in rows, firming the soil as you go. Rake the soil again, removing any more stones. Tread and rake again.
Once you are happy that you have a nice fine tilth that's even then you can sow the seed. Sow it like you did in the picture, then rake over the area again.
Now comes the important bit- irrigate daily. Not just getting the surface wet, but giving it a good soaking.
At present it is still a bit too cold for grass seed to germinate as it likes a soil temp around 10 degrees.
Once germinated you need to let the grass reach 4 inches before you cut it. Use a rotary mower on the highest setting. Keep it irrigated right through the summer.
The alternative is to turf, you'll still have to rotovate etc, but you'll get quicker results.
If you need any more advice, just ask. Don't go to a gardening forum, they're full of eejits, like bike forums really.