Not shifting.
 

I have a 2001 S-10 series 2dr 4wd that doesn't wanna go higher than 25ish. It sounds like it won't shift. I had to leave it on the side of the road, came back later with my brother-in-law. We put coolant in it. Checked transmission fluid and oil. He said when he looked it up the most common problem he saw with my situation was vehicle speed sensor. Could that be my issue? Thanks in advance.

Check your trans fuse. Just a thought. Have you checked for fault codes?