What makes you think they lose interest when you talk? If they just look away when you stutter it could be because they want to take some of the pressure off of you or they might just not know what to do in that situation. If they couldn’t wait for you to finish talking then they’d finish sentences for you in a condescending and impatient way. I know it’s hard but you have to force yourself to start talking more. Once people get to know you they’ll open up around you too and treat you like everyone else. I had the same problem about a month ago when I started a new job. Everyone would start talking to me but when I’d respond they’d start acting super weird and usually didn’t talk to me again unless it was about work. So I had to start a lot of the conversations and after a week or so, once everyone got to know me they relaxed a bit and now they treat me the same as everyone else