Okay since you are new to this I will give you a few pointers to try help you get thru bookings, but remember you never ever have to do anything more than you are comfortable with. (Just because another escorts do something, doesn't mean you have to also)
Firstly don't drink before a booking, you are making yourself more vulnerable to being abused and your defences are much lower, therefore it takes you longer to assert yourself if something is not right.
Secondly lube up before the client arrives, or when they are in the shower, that's what I do, send them off to the shower, hide the cash and lube up and get out of my dressing gown.
Thirdly never do anything you don't want to do, screw the agency. Work for yourself and set your own boundaries. Make up a new name for yourself and never tell clients the truth about your personal life.
Always get the cash upfront and don't be afraid to ask for it either and go with your gut instincts, if a client sounds off on the phone, then trust yourself and refuse their booking, just say you are fully booked and to ring back tomorrow, then block their number or save as do not answer.
Lastly and I don't mean this in a bad way, but you are very young, with little experience of a healthy sexual relationship, maybe you should reconsider taking a minimum wage job, yes you won't make near as much money but you don't sound happy doing this and that shows during your bookings pet. Can you offer cam work and fone sex as a way of getting by also, without having to meet clients, or massage with a happy ending so your not having full sex with them. I know there is no way I could have done this job in my 20's, for me it is about self confidence and knowing I have the experience to make men feel good in bed. Plus I genuinely enjoy it.
The very best of luck and do what's right for you xx
Nat