Just did 70% of the job for a software project in college, only to get the least grade of the group because others were more vocal during the presentation.

The thing that irritates me is that not only did they assume that they can take part credit for my work, they cared more about 5%of a semester grade than their own self respect.

No hard feelings though, because even though I got lesser marks(about 2-3 marks lesser), I gained the most knowledge in the group, which is what matters

I know that. Got such people in 3 projects at university at the same time. Guess where my free time is.
But yeah. We learn the most and others don't care because they got their good grades.
Just head up and chest out, we're the better ones!

You need to go talk to your teacher. Explain your position. Even if it's set in stone there's always mortar, concrete, plaster, and paint. You can change anything you don't give up on.

More importantly, you HAVE to self promote. Not good at talking to people, join Toastmasters. Take a public speaking course. This is one of the most important soft skills. Help you get better jobs, better salaries, better raises, and respect. You can be humble and exercise humility and not sacrifice your self respect. But you gotta be able to sell you.

Good on you for realizing that the best takeaway here was the knowledge you gained. Keep that mindset going and you'll be fine.

And this is why nobody likes group projects in college...

Well it's just like the rest of society.. freeloaders everywhere and people who yell the most get usually the most (and not because they have the best knowledge..)

Yeah, you should able to sell yourself but some people bullshit the way up