4.5 yrs into a disability claim I hired a lawyer who is not helping me and threatening to drop me and thus make me start from beginning, can I leave g

have had several problems with lawyer I "hired" after 2 or 3 denial steps in disability application. Most egregious is his demeaning and loud claim that I didn't turn in a request for extention with his threats of dropping me and making me have to start process from beginning.. I am due for a judge hearing and was considering getting another lawyer to conduct remote judge hearing . Can I change lawyer now without losing application status? Would he still get his share ,if claim approved with another lawyer?