Ok, so to start off I really enjoy playing Black Ops, but I have been frustrated as of lately. I can never seem to get more than a 4 kill streak which is really annoying and I am very inconsistent in my playing.

I follow xJawz on youtube and use his class setup. The class I use the most often is this:

Famas- Dual Mag
Semtex, Concussion, Claymore
Hardline, Sleight of Hand Pro, Ninja
Spy Plane, Counter-Spy Plane, Care Package

My weapons are good and all but I always get caught from behind and from places that I'm not looking from and I need some general tips on how to play the game better or things I should be doing different like classes.

I'm on Prestige 2 and it is annoying because I have put 4 days into the game and I'm only that far. I would very much appreciate tips from people that are good at Call of Duty: Black Ops Multiplayer

The main issue I see is perks, sleight of hand pro is good, but not neccesasary with dual mags, I'd suggest either a new attachment or a different perk, steady aim or hardened are good alternatives. The Famas is a good gun, I have presteiged a few times and find it the best, until Ak-47. Check yourmap, but don't overuse it, get to used to it and you'll get screwed when it's blocked by a jammer or counter UAV. Don't take off sprinting through an area, check your corners, move cautiously, and if your not sure whats behind you, don't be afraid to turn around and look. When checking corners or going through an area, think of crossing a street, look right, then left, then go, no hesitation. Now that I think about it you could use the perk that lets you aim faster, I believe it's called Steady aim pro. As an example I'll give you my only 2 classes.
Spanker:
Primary: Famas w/ Reflex sight / Blue "X" as reticle
Secondary: Pythons w/ Dual Wield
Tomahawk, Concussion, Claymore
Perks: Ghost Pro, Steady Aim Pro, Hacker (Pro before I prestieged again)

Head Hunter:
Primary: WA200 w/ Acog sight (Weird but effective)
Secondary: Pythons w/ Dual Wield
Frag, Concussion, Claymore
Perks: Ghost Pro, Hardened, Hacker

My killstreaks are: Mortar Team (6 kills), Attack Helicopter (7 kills), Attack Dogs (11 Kills)
I keep my killstreaks higher than most people, and I often reach them. I've called Attack dogs many many times, without carepackages. I get my mortars and helicopter every 2 - 4 matches.

I hope this helps you out, I know it's frustating not performing as good as you know you can,
Good Luck!