Difficulties are best used as a learning tool. Figure out what went wrong and how you can improve. That will be more valuable to you in the long run than a success… We all face difficulties and embarrassment at times and no one likes when it happens to them. But giving up is never the answer.

It is possible to be smart or good at something and bad with public speaking. I am good at my trade and even teach people how to do what I do. then my work tells me I am going to go up in front of 40 people and put on some circus show, and all I can think of is how quickly I can write up a new resume and resignation. I stumble over my words, forget part names and chemicals, even the day. You may just have social anxiety.

As someone who was in academia until a medical issue took me out a few years ago: I absolutely, categorically guarantee that your presentation was not the worst ever given. Almost certainly not even the worst that people in your audience have sat through. Public speaking is often not necessarily an academic's best skill. And most people would probably feel sympathetic towards you, especially since, as you're doing a masters, it's likely that you're not overly old or experienced at giving these sorts of presentations. Either way - Anyone who's been in higher education has been there and stumbled through a presentation and felt awful about it. But the big indicators - Did you put in the work beforehand and make an effort to do your best? Those will absolutely shine through even the roughest of delivery. Question-and-answer time can be rough - Sometimes you know the answer right away, other times it's an angle/question that hadn't occurred to you at all, and it's entirely fair to say as much and that you'll have to follow up with them on that one. I'd much rather sit through an earnest but unpolished delivery by someone on a topic they're passionate about than a presentation by someone who couldn't be bothered to learn the material they were presenting at all and clearly has no interest in being there.

Try to hang in there, and don't leave on your own volition. If you truly suck, they'll kick you out.