Being medic doesn't mean you have to have a < 1 k:d ratio. I am almost exactly even at 1.0209 (6359 kills / 6229 deaths). There are a couple things you could practice to help yourself out.
First, remember that your medic bags heal you as well, don't just toss them ALL away for others. Hold one in reserve for yourself. Medic doesn't have armor, but the med packs are even more helpful if you pay attention and use them. If you're running from flag to flag and aren't 100%, run with the bag in hand. If you're prone somewhere capping a flag by yourself, look straight down at the ground and drop 2 packs underneath yourself. If someone sneaks up on you and starts shooting, you will get a couple of 'free' shots because you'll instantly heal yourself.
Second, always look around and kill enemies before reviving. Typically, even if a team mate dies, he got a few good shots into his opponent and you could probably finish him off with a single shot from a pistol. Take him out first and then revive, not before.
As for guns, I find it hard to beat the G36E. The 3-shot burtst forces you to have better accuracy than a full-auto because fully-auto gets more and more inaccurate with each shot. Those 3 shots are in a pretty tight pattern.
And finally, remember that you don't have armor, so as mad scotsman said, don't go bustin' up in the house like Rambo. The G36E is deadly at pretty long ranges so take advantage of that.
Most importantly though... HAVE FUN!
