I'm in roughly the same boat as you, although my record isn't as bad as yours yet (21 losses, 0 wins in ranked). In player matches, I was losing pretty much every single one of them. Maybe I'd take a round here and there, but its not at the point where I'm proud of it. I've swapped characters... initially I was using Sin, and now I've swapped over to Ky to grasp the mechanics of GGXRD bit by bit, and at an easier pace.
Your time training everyday isn't wasted. Just switch it up a bit in training, it takes a while for it to become muscle memory and you need to keep those combos in your head. Spend some time practicing against moves you're having trouble against, e.g Volcanic Viper spamming. That's what I usually try to do. I happened to come across this video somewhere while searching up Guilty Gear guides. I'm not sure if you've seen it before but if you haven't, it might help you out.
https://www.youtube.com/watch?v=xzUQ5FR7TQA
Its pretty lengthy and not on Xrd, but the concepts are roughly the same. This should apply to most fighting games I reckon.
I think that you're in the right track though, don't take the losses too hard. I'm trying not take it to heart as well, since it seems that most people have a good feel of how Guilty Gear works whereas guys like you and me are just starting out. Its perfectly normal, just don't resort to spamming or desperate tactics to win. Take your time and process things.. in fact one of my goals is to not be on auto pilot, but to actually try and observe what the other player is doing. I'm trying to sit back a bit, look for habits perhaps, and try to use that knowledge to get in for some combos. Its not working out too well though, cause I can't keep up with it myself. Keep up the practice, try to play against people more often.. that's one of the best ways to learn.
What I like to do in terms of combos, is to not always rely on the challenges. Sure, they're good for testing your execution but sometimes its better to dumb it down a bit and simply a BnB so that you can land it all the time. Go on youtube and look for normals to use in different situations (anti air, etc etc) and perhaps some short combos that you're capable of pulling off consistently. If its too hard, take your time to learn it, but slowly implement it. I like to start with simple and practical combos and work up from there... although I'm not making much progress myself, but that's what I aim to do at least.
Good luck to the both of us!