I've been doing it for a long time. It's not easy to make a full-time living. There are times when everybody wants you and times when nobody does. You have to pay your own taxes, provide for your own insurance, etc.
My number one advice is to not price yourself too low.
If you are trying to support a family, you can't do it on 300 nursing homes a year at $100. a job. You have to, or at least I have to, make way more than that. In case you haven't noticed, gasoline if pretty high right now. And remember, a one-hour job is really at least three hours of your time, depending on distance and set-up, tear-down, socializing, etc. You must allow time in case some piece of gear malfunctions. You WILL have to go to the car and get a replacement for something now and then. (Of COURSE you have backup of every single item from the cheapest cable to the entire pa system). You are a pro and afford to blow one single job because it might cost you many more as a result.
I have done a lot of nursing homes and it is very rewarding. I love to to them. However I used them to supplement my income from night-time jobs. Nursing homes have a budget for entertainment and by law they have to provide it. If you do it free or very cheap, you aren't helping the residents, you are helping the owners! Too many nice people with good intentions are doing them way too cheap. As long as that happens the market is low for all of us.
I've been lucky to have a semi-steady job at a high-end establishment that pays fairly well. There are very few of those around here any more. After 25 years, mine is very shaky right now because of management changes, so I'm actively pursuing other venues (so far it's working out even better.)
Private parties such as holiday events and wedding receptions are the jobs that pay the most. A few years ago, I arbitrarily doubled my rate for those, and I have lost relatively few of them. In fact, I may get more because of the perceived value idea of "you get what you pay for".
I don't charge by the hour. I have a minimum of $400. for private affairs, more for big receptions, whether it's an hour or 4 hours. (Not saying you can't bend a little for special circumstances, but it's important to be consistent because the clients often consult with one another and know what you charged the other guy).
My second piece of advice is to keep careful records of every penny you spend, every piece of gear, clothing, car expense, phone bill, computer costs, office space--everything. You will need this to keep from giving back too much in taxes.
To get back to your original question, it would be much easier if the music job is supplemental income. I began receiving social security a few years ago. It is far from enough to live on but it helps.
You can do the math. Figure out how much you need to make each week or month. Figure out how many jobs and what rate you need to do. Then allow plenty of room for the slow times. Bank what extra you get during the good times.
Only you can decide if it's worth it.
I have done a lot of these things wrong and learned much of it the hard way. Without my wonderful wife, I would have done the same thing, but my standard of living would definitely be lower!
Hope this helps.
DonM

PS I just noticed Gary and I posted at the same time. Haven't read his yet, but I'll bet it's close to what I said.