For years i have gelled my hair and it has been fine, just the way I want. Now i gel my hair and strands stick up (away from the pack). Some even curl and wave. Some strands appear thicker, coarse, and just weird looking. It may be damaged or something i dont know. How can I fix this problem of my hair strands being "regular" again especially when I gel my hair. My hair even STILL sticks up even if i dont put gel and it goes in ALL directions.

I want to achieve the "shaggy" look so i was hoping that having longer hair would weigh it down but so far no good. My hair is about 2 inches long at the top and back of head. The back part is very "bushy" or "puffy" and when wear the 'behind-the-head' headphones it leaves an imprint. I feel like the hair at the back is just getting bushier than longer  

my hair strands ranges to these:

the guy that cuts my hair said its just the texture of my hair so itll be hard to get the look i want. I think i googled something on hair texturizers that i guess makes "thinner" hair thicker, bulkier. I want something that does the opposite that makes my hair more less coarse, and just goes down with gravity.

the problem is that the hair on the back of my head sticks out (like horizontal but at 45 degrees) instead of just falling straight down along side the back of my head (would this be considered flat hair then?)