>>4>>3>>2 Yes, yes, and yes. Just yes, pretty much.
It's been said, and I'll say it again; academics do not reflect your worth as a person, you do. So the first and foremost step to improving your grades and what not is to not attribute your shortcomings and failures to your character or natural competence. People are bad at things, you will be bad at things, I am bad at things, and it will be reflected from time to time and it can only really hurt you if you let it drag you down and consume you.
Yeah, like
>>3 said, the first parts of college are generalized academic study that don't directly apply to your career of choice but may be foundational to it in some capacity; likely not to the extent that you'd have to calculate which orbital an electron of Carbon is in when you design a machine or fix something, which is why early on the classes are even less reflective of your abilities; once you make it to the real stuff it will be more relevant, and in being able to pursue your goals more directly you will put more of your mind into it and it'll probably come easier.
You are not a complete failure. I think another person can only emphasize that point; you're just making mistakes and struggling. It's part of the unique experience of being a human; we screw up so that we can learn what NOT to do, and then figure out how to do it. Success only teaches you the right way, and in holding on to that, well, that's swell and even preferable but failure isn't a bad thing as long as you figure out how to start learning from it and subsequently applying the knowledge gained. In any case, there are much more to people than our grades and success in life should be measured by more than work and studies, or there's no point to work and studies; over devotion to a cause, ideal, or purpose will dilute it and render it pointless because if the only meaning is attributed to one thing then the achievement renders everything meaningless and that's just silly. Treasure the other things you have, your hobbies and talents; cut back a bit on the free time you make but keep plenty to support your sanity and just keep trying, and you'll go where you go as you go; you can do it and I think you'll be fine as long as you don't let this unfortunate turn of events overwhelm you.
As
>>2 said music definitely helps and notes are nice of course; I recommend as well for things like Chemistry that you just practice a bunch to make sure you see as many problem variations as possible.
Good luck and I hope you find your inner reserves and turn them into a stockpile of willpower with which to slaughter your decadent grades and replace them with your success bred of wisdom~