I was made a 15% partner/member and giving a salary. A year later the senior partner fired me due to my disability and made me a pittiful offer to by me out of my % and is now refusing to show me anything like P & Ls. They also did not include me in the K1 returns and now will not give me any information. What can I do ?

Hire an attorney, make demands and sue for value based on value at time of sale at least.

And review your buy out contract, I can't believe you signed and sold and allowed yourself to be able to be fired. Retired or put inactive but not fired.

And grab the client contact list. Those who love and trust you might stand behind you, especially if your NAME is on the practice. (But NOT as a substitute for what your lawyer will do for you).