Dude analyze your demo and see that you probably lost because you had a lack of impact. Just ignore the teammates factor, only look at how YOU could've done more. You will never progress with this looser mentality of “I did all I could but my teammates sucked”. Even if you dropped 70 and still lost that would’ve meant that you didn't do enough. This is my mentality and this is why I’m always progressing (I’m not bragging, don't get me wrong. But I do get like +100 elo a week at least, so I would say it’s working).
I’ve seen players absolutely destroy their opponents while having under 30 frags and others have barely any impact while dropping a 50. Depends on your play style. If I bait and stay last every round I can probably drop a 50 every game but I don't do that because I actually want to win. Literally yesterday I had a guy that dropped a 30 in my team while we lost 16-6. He did NOTHING all game. Held T spawn with an awp as T and never rotated as CT. He had 0 MVP’s with 4 triple kills. All of these were exit frags.
Analyze your demo, see where you could've done more and keep grinding. GL