OP: I make plenty of money doing this (sports gambling), and I was on the Cardinals with you (+143). As some posters above have explained, the fact the wager lost does not mean you were on the wrong side, or that the wager didn't have an edge. Read what the posters above have said to you -- there is good advice in this thread. I can't say it any better than it's already been said above, so I won't belabor here. I will, however, leave you with a simple illustration that might help:
Consider a (fair) coin toss, having a 50% possibility of coming up heads, 50% tails. Someone offers you +103 on tails, for as many (or as few) tosses as you'd like, wager amount must be $100. You take the bet on tails (getting +103), for $100 per toss, and tell him you want 10 tosses at those odds. He obliges, and the coin is tossed 10 times, coming up heads 7 out of ten. You just lost $391 (i.e., lost 700, won 309 back). Does this mean you didn't have an edge??? Of course not. You did have an edge. Your expected profit on each $100 wager is $1.5. Nevertheless, things didn't go your way in those 10 wagers. In the long run, however, you can still expect to make $1.5 for every $100 wager placed, so you would be wise to wager on as many coin tosses as possible under these terms.
Now here's the harder part (but not THAT hard) -- you need to go find sports-gambling situations that are akin to a coin toss getting +$$ as in the example above. No one here is likely to hold your hand and show you how to do it (there is only so much $$ to go around for all of us), but the info is out there. What you've been doing for many years hasn't worked; you've been laying money on the coin tosses. Throw out what hasn't worked, that part is easy. Read as much on this forum (and others) as you can, and learn.
Best of luck to you.
P.S.: When I was in my 20's, I was in similar shoes as you. Tried everything, thought I knew a lot about sports, but just couldn't win. Then I discovered Internet forums, I read and researched and experimented, and now I get +103 on coin flips.