its all practice son.
i notice you were doing a lot of fsmashes that werent KO's or tippers, just kinda something to hit them with.... not that its bad, a marth that's good with the fsmash isnt a bad strategy and is quite effective on most, everyone will do it including myself. its just that somewhere along the road, you will face someone who will be used to it, and will switch up their game to be prepared for the fsmashes more, and will counter appropriately on the lagtime. that is why you must also be able to switch your game up, so people cant take advantage of stuff. that is a mindgame in itself, to make someone think you are playing a certain style, but to elusively switch it up when it becomes noticable. youre style is good tho, youll start to feel your style become tighter and more refined as you start beating people more consistenly. its all practice son!
btw you, and most all newer smashers are a LOT better than i was after 1 full year of melee playing. its like college transition to a job. college is learning all the info, and then when you get a job, you gotta learn ways to apply that info. proper application comes with experience. in melee,everyone learns the info/tactics, but it really doesnt mean jack if you cant perform and apply in the "real world" (in this case, tourneys). imo getting better in tourney requires many low tourney placings before things turn up.