I have no credit cards and i really do not want one at this point .
That's an excellent start. Me and my wife just got completely out of debt this year, and it's amazing how much money is left over at the end of each month. And you don't need a credit card to use as a deposit for rentals, hotels, etc. Your debit card should work just fine. Debt is dumb. It took me about 12 years to get out of debt, and I'm never getting in it again unless it's a home mortgage.
What I recently did is I took a long hard look at some stuff I had been holding onto which I never use. I made about $500 selling old junk I no longer needed. Have a yard sale and get rid of old stuff. Your wife will thank you!
Having your own kit is a step in the right direction. I'll have spent about $1900 for all new stuff once my kit is fully complete. (I've been certified just a little over a year) I estimate it will have paid for itself after 40-60 dives. As long as we take good care of our gear, it should pay for itself. Also, try aim for the tech diving mindset, which is a minimalist mindset. From your gear choices, it sounds like you are already on you way on this route. There's no need to be a Gucci diver unless you're trying to impress somebody. Just stick with the simple stuff that works.
Not much else I can say that hasn't already been said. Odd jobs are good for extra income. Just don't let your course work suffer!