Poker in my life

This is my first post anywhere sorry for the spelling and grammar and the length etc...

I have been playing for quite a while I consider my self and excellent player when I am in my comfort zone i been up and down not taking it to seriously. One time I deposited $50 on fulltilt won like $5000 playing tournaments (two tournaments actually $27 buying i think third place both times) payed tuition that was it. Put 100 from time to time won/lose some times i would win like$ 500> in a session playing Omaha and moving up in limits really quick so poker has been good to me.

Any way this is the thing I am not currently working or attending classes so I got the free bankroll used the pokerstrategy and the rake kill me , then i got another one from Titan and when all the way to 400 in a day, cleared the 5000 points in about 5 days when all the way to $600 playing consistently 4 tables cash game SH NL50 got impatience lost like $300 moving in limits put everything on black(roulette) and well I am on the street. So now I am thinking in putting my own money so that I could take it seriously $500> more less
Here are the questions :

Can someone make a living ( a modest one $100> a day ) playing SH NL50 I think I can beat this level whit out risking to much: if so what site is the best site for this kind of play.

What kind of restrains should i have:play how many hours,put a lose/ win limit, play only one kind of game, when should I quit a game.

How can I take poker seriously?