Now what

So i have written a compiler for a cool language, let's call it P6, and the compiler itself is written in P6.

What do I do now?

Serious answer:
You will have to write a P6 compiler in another language (say, C + flex + bison) to compile your P6 compiler. It doesn't have to implement the entire language or do any optimization, just the functionality you used when writing the P6 compiler in P6.

Now you can throw your compiler written in C away. Then you'll be able to compile the next versions of your P6 compiler using the previous versions of itself.