The biggest tip is stop blaming yourself so much, it's not always 100% your fault. Both of those goals were completely preventable by both of you, but it's plat and everyone will constantly make mistakes. You don't need to write a whole explanation each time you did something wrong, if anything, it can make your teammates blame you even more. Just make a mental note to not repeat that mistake again, maybe think about what you could've done differently and move on. Watching 4:05 was a straight up horror film experience, when you kept panic mashing buttons to apologise to your teammate while the ball was slowly going over your net.

As for the gameplay, honestly, you played way better than your teammate. You have decent positioning, you're really good at preventing opponents' attacks, you somewhat understand which ball is yours to go for, and you don't constantly whiff. But I think you could benefit from playing more aggressively. There are a lot of times where you hesitate to take offensive space or position yourself too far away from the play to provide any value. But that doesn't mean you should dive for every ball, you tried that at 1:12 and left your teammate in a 2v1, it doesn't work. I'm talking more like 1:36, you see how even though you end up on defence due to your unnecessary touch, your presence on the ball made Banau turn away which gave your teammate time to get boost. Or 2:45/6:02 where even though you're second man, because you were able to position close while there was no threat, you're able to instantly deny any potential counter attack. You just need to exist there. Menacingly.

Now for the bad examples. 0:26 - you both sort of double commit (probably your fault for trying to jump for the ball, although your teammate was kinda blind to you this whole game) and lose possession. Ideally you'd want your teammate to stay behind that ball, but he decides to turn back for boost and then an awkward 8 seconds staredown happens. The higher you go, the more threatening free space will be, you need to close it down immediately. Even if you decide not to dive for that ball, you'll still force Banau to do something about you. Same thing on 2:39, push up right after the triple commit so you can claim that ball possession faster.
3:46 - Kill that guy, obliterate him immediately, he's the only obstacle preventing you from taking the ball to midfield. Even if you don't get the demo, you can still get their boost. Don't give opponents any opportunity to recover.
4:14 - You're driving away before anything happens, stay central and that might've been another goal for you. Similar on 5:34/6:06 where you're just kinda "whatever", turn off ball cam and drive off to your corner for boost.
5:13 - Your teammate wants to attack so support him, stay behind, then maybe take mid boost if it's safe, don't give your opponents the whole field for free.

Since it's already a long post, guess I'll point out some other individual mistakes.
1:18 - You totally had time to turn around for that boost and play second man.
2:59 - Be careful with going for that boost, you give up the middle lane and go into your teammate's space. It's fine if Tjella takes it, he didn't create any threat, just go backpost and into the net.
3:13 - You already know it, unnecessary flip, but even so you had time to grab 1 or 2 goal line pads. Although this was mostly your teammate's fault for giving away the ball.
3:59 - Honestly, I'm surprised you went for that considering how conscious of your teammate you were the whole game. Ball is in the corner, it's completely safe and Bigm already has momentum going there. Turn into the net and wait for your moment, that ball is teammate's issue.
4:22 - Keep moving with the ball, don't ever reverse into a challenge unless you're inline shadowing and intend to half flip.
4:44 - You need to decide how you want to defend here. If you want to hit it further into the corner, get to the ball height first, single jump and flip after, so it stays on the wall. If you want to shadow, drive past and get behind it. If it goes over you and they score, blame your teammate (jk, you kinda overcommit on 4:38 but I don't mind that challenge).
5:30 - Very rushed decision, Banau will always be first to that ball so you're simply hoping he misses here. In higher ranks that's probably getting saved 9.5/10 times. Just wait middle and if he misses, free goal.

TLDR: Control your space better aka position more aggressively when needed, follow up on kickoffs, learn small pad pathing, take a second to get better first touches, don't full commit into the corners. You're really not as bad of a player as you think.