I only stutter when talking/reading to myself?

I only stutter when talking/reading to myself? This has been an increasing problem over the past few years. I'm in my mid-thirties, and before maybe 5-6 years ago I never had a stutter in general. I still don't stutter when talking to other people, but I find that I have a very hard time when either thinking or reading out loud when I'm alone. Ihave to read the same thing over and over again. This also isn't just vocal; my mind catches on it and I have to repeat it. It's made reading a lot harder, and thinking itself is more fraught. My only theory is that it could be OCD related, as though I have to say or even think something the "right" way, or maybe with full clarity? It doesn't make sense to me, and I don't know why this has become a problem now. Has anyone else ever had to deal with something like this? And would people know why this isn't an issue when actually talking to others? I always heard stutters traditionally affect people the other way around, when they're conversing instead of just by themselves, and I've never heard about an "internal" stutter.