Let me put it this way: The Sniper is a difficult class!
There's a lot of things you have to put into account. First off, Many will be going straight for the snipers since they can be a serious threat. Hence, being able to defend oneself in close combat and outsmarting huggables is absolutely essential. Only few snipers are able to fully defend themself against anything up close.
Second, getting the right aim leaves you vulnerable to "backstabs", since you can't see what's behind you. Being able to multitask and knowing where all your opponents are is also very important. But if you have a good memory and is able to handle a few things at the same time, you might have a pretty good time as Sniper - just know, that it takes very much time to become a good sniper since there are so many small things to learn.
Also, how good you do often depends on the rest of your team - and there will both be ups and down when playing sniper. Me? I've been practising for half a year and I still haven't perfected my technique ^^