Ihave a thick lawn but the grass always seems to lean and fall down so when you go to cut it it will just skim over some parts and cut twice a week WHAT DO you DO?

Sounds like the variety of grass is unhappy with your mowing height. Certain grasses, ie; bentgrass or poa trivialis, lean over at less than 2 1/2 " heights. Blue and rye grasses can maintain themselves at 3" mowing heights quite nicely. Once you have identified the grass type, the mowing height can be adjusted accordingly.