Okay man, I can tell this post was made immediately after a deep trip into the salt mines of For Glory because, to be frank, we've all been there. I've made my share of self-hating Facebook posts after a series of Ness taunts and failed Dancing Blades.
As said already, Robin is a fairly difficult character to use. That being said, picking Robin isn't necessarily you robbing yourself of victories.
I recommend looking at
1) Robin tutorials, combo videos, matches (with players proven to be good), etc. on YouTube and whatnot
2) Smashboards' character forums, specifically Robins'. From what I've seen, people don't get away with being jerks here, so don't be afraid to ask questions you may think are "dumb" (there's really no such thing as a dumb question, at least to me anyway). A lot of us came here when Smash 4 came around, one popular reason being is to "git gud", so many of us are in similar boats to you.
2a) Also, if there are certain characters that are driving you insane, go to those characters' forums and you might find answers as to how to get around some of the popular tactics. I'm sure people will agree with my on this; one of the best ways to beat people is to know the other side of the match, the opponent, the character you are fighting.
Another point I really, really, really want to stress to you (if you're even looking at this post) is that For Glory is one of the worst online competitive services I have ever seen in a fighting game. It is such a disservice to you, and even moreso if you use it as a scale to measure how good you are. Are you really "one of the worst players in NA"? Even though....
1) there's inherent input lag
2) there's visible lag and choppiness
3) there's a matchmaking system that can be described in one word, that being "NOTHING"
3a) no, really, i doubt there's even a system of pairing players together other than "WHAT'S THE NEXT OPEN ROOM???", because frankly there is no reason to pair me up with players who play Little Mac and Jolt Haymaker off the stage, or someone who INSISTS on trying to Kirbycide me TEN SECONDS INTO THE MATCH. For Glory stats? Global Smash Power? I doubt those do literally anything. (Someone please tell me I'm wrong)
4) the stage selection is limited to Final Destination and Omega stages with walls. Remember other legal stages like Battlefield? What about those? No?
5) Many of the players are willing to go beyond mere taunting and say nasty things, because apparently winning wasn't enough
Just maybe you're not very good at this game. That's always a possibility. At least you came here though, with this attitude that shows that you expected better than what you see. In other words, you're not satisfied with where you're at and you're hungry to get better. That puts you above a lot of For Glory players who refuse to adapt and resort to things such as picking the same character you pick and senselessly spamming 2 or 3 special moves. Talk to people here and ask if anyone is down to practice with you, especially players who would say are on the same level as you. Of course, input lag will always happen, but an environment designed to make you improve is better than an environment such as For Glory that is just-- man i'm gonna stop i already showed how salty i am about it lmao