Not that I'm the one to talk since you already know my situation...
But in general, I've approached my betting hobby as pure entertainment value. I disagree with others who state that sports betting is an investment, especially from that Aussie guy who apparently has sex all the time.
Because the risk of losing money is so high, you basically are banking on luck to get your money back because the X-factor is all sports outcomes here is well, human. In other words, there is no past history of clear demonstrated market return in this game because humans are unpredictable, and most lose more than they win.
I equate the hobby similar to buying lottery tickets (except with much a better chance to win), and I accept the fact that I may lose all of my money. If you can't accept that, then you should probably start with a very small bankroll and bet dollars and cents or not play. This is my current situation since I am insistent that I will NOT reload my BR. If I get broke, then I'm out of the game for awhile until I truly believe I have some more disposable income. (Won't be for awhile since my wife and I just had a daughter!)
That said, I believe if you do want to approach sports betting as an investment, you absolutely cannot do some of the ridiculous betting options like parlays or "special plays", no matter how tempting. If you look in any of the other forums, you can see that parlays full of heavy favorites still do not win all the time. Sure, there are some exceptions like that guy who had a crazy 24-team parlay in NCAA, or the guy who started with $5 and got up to $5000 in 3 weeks, but in general, the odds are very much against the bettor.
In general, there is no magic formula to make money in this game. In my opinion, start with money that you're willing to throw away, and enjoy the sports that you bet on. Otherwise you'll just get angry at touts and others who believe they know more than you, or are willing to try to prove that they know how you should be managing your money. Just remember at the end of the day, you are the one that clicks the button to confirm your bets.
If you want a true challenge on using sports betting as an investment, limit yourself to risk $10 a week. Find the absolute BEST plays that you think will hit each day, and only limit yourself to 2 plays a day @ $1 risk per play. This absolutely takes mountains of patience and persistence to get anywhere, but it's smart and allows you to understand how much you can trust your gut instinct versus really finding the people that are best at analyzing or picking plays.