Generous estimation would put 0.3% of people in the USA who know or use ASL. So you'd be able to communicate with 3 in 1,000 people. Narrower estimates would reduce that by half. What efforts have you made to improve your fluency? How many SLP's have you worked with and for how long? As you indicated your fluency has gotten worse and worse, that's a positive indicator that your fluency isn't immutable. i.e. it's gotten worse, it can get better.