Not improving is not a slump. You will know it when it hits you. The fustration! I too have not improved in awhile. But I remember back when I used to plateau every month. The advise I would give you back then would be to play against players about 100 points stronger than you hence gain confidence. You won't learn from opponents who don't punish the mistakes you make over and over again.
not improving anymore

Analyze your games on your own without the help of a computer. Mostly look for different positional plans in the game, critical decisions and how you handled them, are you aware of the value of your pieces and trading or not trading them etc etc. Then post the games on here for people to help you analyze. This is probably the easiest way to improve your understanding of the game
I have progessed so far so fast but now I am totally stuck. I worked my way up to 1700 blitz from 600 but I haven't progressed one bit in about 3 months. My only form of practice is playing games and I was wondering if anyone had some good practice techniques that could help me break through my slump. I am not very good at positional play and lose most games that have quite, not tactical positions because I start dropping pawns. I don't know how to improve positional play other than playing games.