Spicer manual tranny problem

I have an 89 International 7400 with a spicer manual transmission in it. I put it in first gear but didn't get it all the way in and when I released the clutch it popped into neutral. Ever since then it has been hard to shift into first or reverse when at a stop. Sometimes I have to push it into gear while slowly releasing the clutch. Also when I get it into gear and release the clutch the engine acts as if the brakes are partly engaged or some other resistance. Truck is drivable but definitely something wrong. Any ideas on what might have happened here and what is involved to fix it?

 

No ideas? Did I post in the wrong section?