I need help badly my brother 14 he still sucks his thumb and has a lisp

hi my brother is 14 and he still sucks his thumb he has a really bad lisp plus a mive gap in his front teeth i cant afford a speech therapist and he's already had braces what shall i do to get rid of the lisp and stop him sucking his thumb he keeps on getting teased and currently not going to school because he's being bullied over it please please help