Well i see it this way, practice your combos and different situations when you first start the game.
Get past that and move to arcade mode. Start off whatever difficulty you want whether it be Medium or Hard. Gradually make your way to Hardest when you feel comfortable. Keep doing Hardest playthroughs and practicing to get a feel on your characters again before you jump back online.
Finally, you have the internet, learn them matchups from there and apply it to your gameplay
I really don't have the right mindset for learning a fighting game right now I will try this soon buut my way of learning a fighting game has worked for me so far, i'll try yours but arcade mode doesn't help at all for me.
Arcade mode saves you the frustration.
You can practice calmly, and at your own pace.
If so, then just drop it all together until you feel like picking it back up, ya toilet