I'm not lvl 30 yet and the majority of my games start with both teams just autoattacking minions, facechecking bushes, and just being super aggressive from level 1.

Anyway, the real problem is when my partner decides to jump on whatever enemy strays within range and chase him to his tower while being hit by minions and the enemy lane partner. If I help him, we might get a kill and get away, but we might also both end up dying. If I don't help him, we might still get a kill but he is guaranteed to die and yell at me for not helping.

I've tried asking lane partners to not be so aggressive, but they don't listen. I also don't believe in feeding the enemy team my partner just to teach him a lesson if there's something I can do to save him.

There is honestly zero you can do to prevent what you are describing. There is also no right or wrong answer to your dilemma as you already see the pros and cons. Sadly, it's when you get into a bad lane match up with a premade, and your the odd man out, that will make you honestly want to uninstall the game.

Wish I could give you better advice but just know your limits and all others be danged. I would much rather have you be a bit conservative and not chase, reset, and do it again as both being killed and they push your tower early and have two kills.