Okay, so you are clearly in a very difficult situation. However, if I may give some advice:
Firstly, while sex work is work, you should definitely try looking at other employment opportunities. While it is dependant on where you live, wages for teens in the US are averaging around 15/hr, according to online resources. While it probably won't be a hundred in a day, it ought to be safer, physically, mentally and in terms of STDs.
Second, if this is the best path that you can think of, keep protection on you, be read up on abortion laws in your place (as it is unfortunately the US), keep some sort of self defense weapon on you, and have some friend who is aware of what you are doing, and knows your location. Do not let yourself be pressured into having sex. Feel free to refuse any request that makes you uncomfortable, whatever the pay off may be. People- adults or teens- might try to exploit you. And get tested for STDs. Again, this being the US, your insurance plan will probably play a role here, but let me assure you that one of the worst things that you could do is ignore an infection.

Lastly, on the economical side of things, do not allow yourself to enter into a contractual situation with anyone. And keep adding money into an account of yours- a fund that you could use to escape the situation, if the need arises.

Best of luck, and do tell someone irl, so you can have support and a safety net.