You can take notes, then generate Minutes of Meeting, or Minutes and send them to everyone who should be in the loop, augmented with your remarks, annotations, links to useful resources, and most importantly: action items. I shared the format I follow in another thread, in point 1.1 "Taking meeting notes".[0]
You cam'be interrupted in text. It also forces you to br clear and concise.
If people find your insight interesting, you'll be asked for your input more often than you have one.
This is a low stress way of getting the opportunity to speak.
Also, have you talked about this with your manager and did they offer some pointers and a way to make you heard. For example, in a crowded meeting, someone says something. You comment to your manager, they get the room's attention and hand it to you. Or they ask you from time to time if you want to chime in and get you speaking time. After a while, you'll get more comfortable speaking as you would have had the opportunity to do so.
I think it would be useful to talk with your manager.