Ive escorted for donkeys years and never had a problem with burn out etc but years ago I did have a Dom friend in London who I visited once and I spent the day helping her out and I can tell you after that 1 day I left with a banging headache or migraine and I felt physically and mentally drained and exhausted.
Dom work is hard mentally and physically and escorting is a piece of piss compared to that..Don't forget you will need a dungeon or something similar add to that all the equipment you will need to buy (not cheap) and you will have to have complete faith to know what you are doing is what the client wants because many of them don't have a clue and so expect you to somehow understand what they want and cater for their fantasies.
I completely agree with all that Helen said above. Even if you decide to cater for the softer end of the Ds/Sm world you must have a natural confidence and complete understanding in the services you are offering and of the client's often unspoken expectations, wants, needs and limits and limitations. A lot of things can go wrong or cause injury if not carried out or observed correctly, even with the softer things.
It can be a psychologically intense service for both parties. There may also be a lot of "needy" out of hours contact via emails/phone/texts etc which need to be managed appropriately that can also be very draining and tiresome.
A Dominatrix is not, in my opinion, something you just decide to try and be for an alternative income.
Personally, if I were struggling with escorting I would struggle with Ds/Sm even more due to the heavy expectations clients would have of me. There is a lot more "take" with these appointments, by that I mean the Dominatrix carries a big burden of expectation that in the main is about indulging/satisfying the submissive, which unless of course, you are really into the lifestyle and this satisfies your own wants and desires etc you might not find it very fulfilling.
Sorry if I am rambling, it's just that it is a very complex world to try and explain and without using a lot of clich?s!