you certainly have a background that speaks well for possible future success. Your profile is not completed so it says nothing about you.
You need to get a personal trainer certification and obtain liability insurance if you plan to work for yourself.
Also keep in mind that there is more to personal training than dealing with injuries. You also need to consider the marketing aspect of the business. I assume that you work at a physical therapy company where clients are assigned to you. In personal training, you have to go out and find them even though your PT background certainly gives you a leg up.