I think it is possible to make money in this business but there are three points to bear in mind: you have to be good at your work, you have to be professional, and you have to have a business mind.
Being good at your job is obvious and it takes a lot of practise, but a whole business name could collapse if you produce shoddy work. I think it's important to do the best training you can and practise as much as you can and to never stop learning. This site certainly helps with that.
Being professional is important because it makes people treat you like you would want to be treated. If you look smart, turn up on time, are strict about rules that you set when you are working (whatever they are), and don't allow customers to treat you poorly, then you'll begin to build a business where you are treated with respect.
You have to have a business mind to turn a profit. You could be the best therapist/technician in the world but if you don't care about the money side of things then it could go wrong. Know your costs, charge for your time accordingly, and set your prices appropriately. Don't let anyone pay less than this (apart from your mum, sister, best friend). Buy good quality stock only when you need it. Don't be afraid to put prices up when costs go up. Don't forget to factor in overheads, whatever they are.
Stay strong. Setting up a business, whether it's mobile, freelance, or in a salon is hard work. One poster said it took her three years and I'd say that's average. If you want it, you'll work for it and it will be worth it. Never give up, and check Lynne Baker's thread on how to promote your business for ideas.
Good luck.