Good advice from imsh.
My advice is to accept that you will lose approximately half of your games no matter how good you are. Try to take all emotion out of the game. When you lose, try to think objectively about what went wrong and what went right. Take it one game at a time and try your best. Try to find out your weak points and make them stronger.
 
gl hf

Some sound advice already here. I'm just starting out and I have yet to win a match, so have patience. I was going to win a 2v2 match but my fucking router cut out -_- I was so pissed.

I'm pretty new and inexperienced myself so if you wanna add me to play sometimes my username is Doctor and my character code is 924. This goes for anyone reading this.

If you're rich, you're losing. Always scout and plan for to either expand/build army/tech up. 

People have said all I had to say, the only other thing is that I wouldn't worry too much about micro or build orders or fancy stuff like that, just work on the stuff listed above (keeping money low, constantly building workers, etc.) and you should do fine. Don't even bother trying to micro or come up with a unit composition, just 1a/ or attack move with your shit until you can multitask better.

4 Gate.
That'll win you a butt ton of matches lower level. BUT don't rely on it cause you'll get punished later on. When i switched to Toss I 4 gated a fair bit while I got used to the race but then switched into 2 gate robo to get Immortals or Colossi out.
And also, don't underestimate how awesome sentries are. Guardian Shield and Force Field are amazing.
 
@Afroman269:
nicely done. the first win is pretty awesome.

Day 9.. Nuff said.

"Never not be making probes." - Brad Shoemaker

Make more marines!

Pretty sound basic advice.  All I have to add is if you want to work on a part of you plan, work on one thing at a time.  Don't work on always building probes, always macroing, and keeping an eye on the food count at all once.  Do one thing at a time, and you'll improve much faster at that thing.

Scouting is ESSENTIAL
You need to do what you can to see whats in your opponents base. 
That can be hard sometimes specially against a walled in opponent but even scouting the ramp can tell you loads.
For example if you run to the top of a ramp and see a butt ton of MM with a Medivac floating above it and another Barracks not far behind the wall off, obviously you have a bioball to worry about. If you see a couple marines and a marauder and nothing else you can make a pretty good guess he's teching up to something and it might be time to apply some heavy pressure. 
And leaving a worker unit just outside his ramp is a good idea so you know when he moves out.

well a problem i always had was trying to tech up to big units like colossus without getting enough zealots and stalkers to support em.

My advice to go along with the obvious stuff that everyone has already mentioned is NEVER TAKE A BREAK!!! I've been really busy with Christmas stuff, a new girlfriend, and starting at a new school this semester, and because of that I have taken about a month off from playing this game like every day and DAAAAAMN do I suck now. I came back to my top rank platinum position and realized that I suck now because everyone has gotten better and I've gotten worse. You just have to stick with it and eventually you'll get better, you just gotta stay with it.

" 4 Gate.
That'll win you a butt ton of matches lower level. BUT don't rely on it cause you'll get punished later on. When i switched to Toss I 4 gated a fair bit while I got used to the race but then switched into 2 gate robo to get Immortals or Colossi out.
And also, don't underestimate how awesome sentries are. Guardian Shield and Force Field are amazing.
 
@Afroman269: nicely done. the first win is pretty awesome. "

" well a problem i always had was trying to tech up to big units like colossus without getting enough zealots and stalkers to support em. "

" Scouting is ESSENTIAL

Best Day[9] video for noobs.  This was seriously a breakthrough for me.
 
  

There is no better tool than this:
http://www.sc2mapster.com/maps/yabot/
I'm not kidding, this is one of the greatest practice tools for anyone from Bronze to Gold.
Just pick one solid build orders and stick to it until you know it by heart.