Your biggest problem is that you are your own worst enemy. You are being too critical of yourself, and it keeps you from making any mistakes.
No one, but NO one, writes everything perfect on the first take. So here's my advice.
Screw up. Screw up a lot.
Once you quit being gunshy about coming up with a few bad rhymes, bad ideas and songs that simply don't work, you'll get a couple that actually DO work. So keep writing and performing, and taking those chances. And maybe someday, we can work together.