Is it time for me to start my own business?

Sure! But only if you have the know how, all the right legalities, tools and financing you need.

you can try and theres grants that will pay you to start your own business

Are you fully licensed and don't just 'know the codes'? It can matter. Have you talked to your current boss about taking over more jobs or such?

If you're doing this right, you don't want to do this under your name. You need to start a limited liability company. This protects your personal assets (house, car, savings, etc) if someone sues the company. You should be find a local lawyer to help you for not too much money. You may also be able to handle it through online resources.

Once that's set up, the tricky part is breaking away without pissing your boss off. You have to decide how to handle that based on your knowledge of him. If you're taking side jobs which he thinks should have come to him it will get ugly. Ideally, you'd be able to discuss it with him and explain what you want to do. Be prepared to never work for him again from that day onward if he's not the understanding type.

Do you have a state contractor license? Do you have money saved up to live on for several months? Adequate tools to complete jobs you plan to take? The knowledge of how to manage the record keeping and reporting required? Do you know how to report self employment income, what it involves to hire on employees, etc? You want to stay in good terms with current boss, for references. If it were me, I would probably let him know my plans to go independent and hope he is willing to keep me on a lighter schedule for a while until things get going. He might be willing to mentor you through the process; though if he is already short staffed he may just show you the door.

Start with small part time side jobs without insurance at first. When you comfortably get 15 hours a week at that, then you can try either cutting back to part time at work or quitting. Your boss may let you gradually cut your hours if you are good but he does not have to.

Business cards are cheap so go ahead & get them now. Finding enough work to keep you busy 30-50 hours a week might not be that easy especially year round so Id suggest offering a notice and leaving on good terms. Maybe even cutting back gradually as I suggested so as not to burn any bridges. (You want to be able to come back if push comes to shove)

You'll never get rich working for someone else. You'll need to have a competent and honest helper. Paper work causes most new businesses to fail in the first few years. You may want to start part time, if you can. It's a big step, but with hard work, you will be ahead of the game in a few years. Good luck.