An "ambulance chaser" is a term that is used to describe a professional desperate for clients. You usually see it pertaining to lawyers persuading clients to sue even if the case isn't strong. So basically she's saying she doesn't want you to stay in therapy for HER benefit.

I say it's time to find a new therapist. Don't blame yourself or get roped into the "client is pushing the therapist away" excuse. Sometimes you have to put the responsibility where it belongs - on the professional.