Transmission weirdness:-(

Hi I have a 1990 2wd v6 4runner. Last night on the freeway with no warning sounds jerking smells or anything the rpms went up and I had no gear. I got it over to the sholder and checked the atf and it was fine not hot no burnt or burning smell level perfect. I nothces in to gear with the gear selector nicely but its not engaging at all making any noise or anything. No external leaks and I dont hear any internal disturbance. Its so odd cause it has been rock solid and never slipped jerked clunked or anything. Please help. Im a single parent and have no way to take it to a shop. If I knew what it was I can do it myself. Good at fixing not diagnosing:-) Thank you very much!