Short answer, I believe so. While there can be games where it can feel like you’re playing your heart out only to lose. In others, the outcome of a match can be very much decided by your actions. Flanking an enemy by taking a side passage to the point instead of the main thoroughfare can result in a surprise pick/momentum that can help your team get on the point quicker. The better to capture you with, my dear! 
Longer answer, there can be a lot of criteria that contribute to the success of a play.
Did that Dva see your attempt to sneak into the back line, for example? If the answer is no, then by all means, try to make the most of it!
Then again, if the answer is yes, then we have a lot less time to get picks than we thought. 
Sometimes, you might be struggling, but then make that choice pick that saves your team. A timely headshot on a Cree attempting his ult, for example. The immediate benefits of such a play cannot be underestimated. And you, my intrepid teammate, can take confidence knowing that you did that. 
It’s no surprise to anyone here when I say I like playing Widow. I can, at times, be stubborn and stay Widow. Others I recognize when Widow has done her job, and switch.
I try not to take victory for granted, but if your team has the momentum as well as the point, and the clock is ticking toward overtime, you might want to swap to support, to help drag your teammates over that finish line. To the sweet taste of victory! 
(There’s no emoji for a Viking drinking horn, sadly, but this’ll do!)
There will be games that feel impossible. You will inevitably backfill into such games. Try not to get discouraged. Easier said than done, I know. But you will always play better with a positive state of mind.
Lastly, and I know I’ve said this before but it bears repeating. Have fun!
If you’re playing OW, it’s because you chose this game from a library of other games. Chances are, we both continue playing for the same reason.
Because it’s fun. Or can be. Which should be the reason to play any video game. If in fact, you stop having fun, then OW has failed this all important criteria. Take a break/play something else for a while.
I always seem to play my best matches, win or lose, at the beginning of a session when I’m freshest.
Take what I say with a grain of salt. I know not the nature or intensity of your own games. I don’t play competitive, probably won’t. I don’t think I have the temperament for it.
I’m just someone who still enjoys the occasional round of OW.