When you want to open packs, remember how shit they are and how annoyed you get afterwards for wasting money on them, remember what $40 could get you outside of gaming. Think of what you could've bought with the $400 you've spent so far too, think of how you could have bought x amount of games or where you could've gone. Write down how much you've spent on FIFA somewhere near where you play, some place you'll see when you're playing the game so you can't ignore it.
Try to stay away from YouTube videos involving pack openings as well, don't tempt yourself. Same goes for this place, try to spend less time here/ignore pack opening threads.
If you still want to open packs, open bronze packs instead, especially at this time of the year when the ToTW is made of mostly silver and bronze cards.
This post is very important to the future of FUT. I'm sure EA gets thousands of parents complaining to them about this game and how it promotes gambling, addiction etc. i think this why they need to do something in FUT 16 and change how much coins you get from actually playing the game . Win or lose you should get way more then 400 coins a game . It's ridiculous this poor kid spending all his money on this game. EA DO THE RIGHT THING AND STOP BEING GREEDY!!!
I was nearly in the same boat as you, started playing FUT last year and loved the thrill of opening packs. I probably spent about $100 or so early on and I was very disappointed in what I had gotten back. Fast forward to the World Cup mode, and I ended spending about 750k of my earned coins through trading on the WC packs.
I got a better return on the WC players, but absolute garbage in the 5k packs in the normal FUT mode(To clarify for those that weren't around FIFA this time last year, every World Cup packs had a voucher for a 5k redeemable pack in regular FUT). My packs were so bad that I actually made myself stop and keep the 200k I had left. From that point on, I pretty much got over my own pack addiction. I've probably opened 40 gold packs at most this year, all through FIfa 16 coins and spent only $10 in real cash.
Whatever happened has happened, you won't get your $400 back, but just take this as a lesson and remind yourself how bad the value you get in return from packs is and go from there.