Is my stutter "unprofessional" and does it make me sound like I don't know what I'm talking about?

Is my stutter "unprofessional" and does it make me sound like I don't know what I'm talking about? I'm very upset right now. I am an engineering student and just returned from an important lab demonstration where I presented a food processing system of myself and my team's creation. While I was giving my spiel, I notice my two teammates with looks of horror on their faces, and one of them is mouthing at me to slow down. I thought that I was doing very well, my stutter tends to manifest itself in "ticks" where I get stuck before saying a word and have to make a "tick" noise to get it out. I had almost completely avoided these during the presentation, but I had compensated by talking at the speed of sound, apparently. I have gotten much better at avoiding awkward interactions regarding my stutter by apologizing saying, "I'm sorry, I have a speed impediment." I do this continue on like normal. Afterwards the head of the Chemical Engineering department pulls me off to the side along with a couple of engineers working in industry. This is normally *super* good, and it means that they want to offer you a lab or co-op position at their companies. Instead, they all start going on about different ways to talk around my stutter. The gist of it was, "I could understand what you were saying, but it sounded bad and was unprofessional." I've been trying really hard to put myself out there by being an great student, always going above and beyond and participating in these design competitions. It feels awful being put down for a speech impediment that I have spent 12+ years in speech therapy to control. I already have enough against me being a woman in engineering, but now I stand out for being "that girl who can't talk good." Does anyone have any real advice in responding to these situations? My stutter is going to happen, it's just a matter of whether or not I can avoid an awkward moment after I stutter.