Starting a buisiness
if you have a customer base, I think you can do it. The cost of the compressor is not that bad, i have not idea about a hoist or lift. Check with the SBA they offer loans for small business and have plans tailored for people in your situation. Do you have a special interest going for you, meaning are you minority , vet or anything because there is also grant money out there to start a business that you dont have to pay back. the fact is you will never get rich working for someone and if you have the skills and reputation and the market will come to you then it is no problem.
You need to sit down and do a budget , rent , utilities , payroll , stock and inventory and figure your start up cost and then an average monthly cost. You will also have to come up with your charge sheet per job, which i am sure you already have. Figure out the numbers , do the math and see what you have to make to turn a profit. if the number add up you can do it.
The biggest thing is to get over your fears and go for it, just be smart about it.