Admittedly I can only help someone who wants help, but since this is the career choice that has been made, and since my help isn't wanted I'll offer advice, and the little bit of knowledge that I've gleaned from the others I've known who chose that particular profession. You can take it or leave it as you see fit.
Find a low cost clinic you trust and get tested regularly and often.
You will probably be infected, try to be ready for it.
Always make sure someone knows where you are, if they know who you're with even better, but at the very least you should have a check in schedule with someone you trust.
Learn how to defend yourself with a variety of weapons, and bare handed (learn from anyone who will teach you, you will need it)
If your gut tells you that somethings wrong it is, take whatever action is necessary to safely extract yourself from the situation.
Never assume that you are tough enough to deal with any situation, there is always someone else out there tougher, and they will have absolutely no compunction about damaging you if it gets them what they want.
Fatigue, physical impairment, cockiness, and fear are all traits that will make you a target.
The freaks you will encounter will be nowhere near as benign or easily dealt with as the handful of abusive relatives and prospective date-rapists that you may have dealt with so far.
You will be assaulted, try to be ready for it.
You will probably be raped, try to be ready for it.
When you are assaulted or raped, the law cannot be counted on for help. Once you are known to them they will, at best arrest you, and at worst take their own turn at you.
Spend every possible moment of every day assessing your situation, know where your exits are, and practice reading people.
Buy a good pocket knife with a thin sturdy blade, keep it sharp, keep it with you, don't let anyone else see it or know that you have it.
Learn about human anatomy, it might save your life.
Learn a bit of ditch medicine, it might save your life.
No matter how bad things get, avoid recreational drug use, situations are always fluid, impairment can be and often is fatal.
Condoms are unpopular and expensive, and most of your clients will refuse to use them, but carry them anyway because some occasional protection is better than none at all.
In the eyes of the mainstream society (law enforcement, medical, media, etc.) you will be less than a person, expendable and deserving of any unpleasant thing that will be done to you.
Be ready to take matters into your own hands.
Learn to bury your emotions and reactions. A lot of freaks are as excited by the reaction of their victim as they are by the act's they commit.
Take a part of yourself and hide it away, it will be your only way back if you live long enough to want to come back.
Some people enjoy pain, so methods of disabling an attacker that rely only in the infliction of pain without corresponding bodily damage cannot be relied on in a pinch. (Not everyone can be taken down by a kick to the groin)
Learn to spot the physical symptoms that indicate weather someone is under the influence of drugs or alcohol, and to what extent... This will not only help you gauge how erratic their behavior is liable to become, but also their level of impairment which (as mentioned earlier) can be used against them in a pinch.
Visual inspection will not tell you weather or not someone is infected, neither will taste or smell or any of the other popular myths.
Never assume you've seen the worst humanity has to offer, we are an adaptable and creative species.
There will be some folks who will want to own you or sell you their protection, avoid them if possible.
Learn where the main arteries are in a person.
Learn where the major organs are in a person.
Read a book every week, it doesn't matter what it is.
Be careful not to establish predictable patterns of movement or activity, these will make you a target.
If you need to escape I will help if I can, but I will only do it once, and only if it is understood that certain ground rules will be adhered to (as much for my safety as yours).
Be safe, insofar as that applies.
Always remember that (regardless of what tomorrow brings) today, as I write this, I want more for you than you have ever allowed yourself, and that I love you (possibly more than you will ever know). I do not agree with the situation but there is apparently nothing I can do to change it.
Try not to end up like the other two I've cared about.
O. L. G. 1978-1996
A. K. C. 1976-2007
Or the dozen or so that I didn't care about.