I feel like I am getting dumber the older I get

I used to be able to speak very well and now I find it hard to get words out and I stutter now and it doesn't make sense to me. It makes me very insecure, but no matter how hard I think before I speak, it doesn't always come out right :( I don't get much interaction with adults most days because I am a nanny and I literally talk to babies all day.(10hrs) They are only 3 months old. I take math online, but that's it. I get really nervous around people now and I can't seem to look people in the eyes. I don't understand what's going on with me. I used to be pretty social