Do / play something else instead. Maybe you're just sick of it at the moment.
And it's funny to see people posting things like "get a gf" if - for SURE - 90% of them don't have a gf / bf / whatever as well.
( If someone flames at me now yellin' "U DUN HAVE A GF AS WELL", I'll laugh, since I'm a girl. And I
DO have a gf.

)
Honestly, your life can't be in such a bad state that you have nothing else to do than playing smash.
But who am I to judge you? It's up to you, I can only give advices.
Mhm... something just popped into my mind. It's probably the same with, like, everything else.
I love to draw and I'm on an Art School and whatsoever, and sometimes I just dangit CAN'T draw AT ALL. At least no "private things" - the things for school are going well, but jeez, it's making me sick to not be able to draw anything else at all.
Maybe it's the same for you, but the other way 'round - then you should play Brawl for the mere fun of it. That's what Videogames are for anyway - you play them for fun. Of course there's competitive gaming and tournaments, but if you just can't win at all, go back to your roots and just play for fun. Or ... not at all.
You'll get over it for sure. Just don't whine about it, everyone - and I mean EVERYONE - will someday meet a situation like this. Maybe not with Brawl, but with other things.
And they all got over it so far, so don't give up.
~ Atsu
PS:
Why is my name still "Kriegsseele"? I wanna be Atsu! >_>