TH 400 won't shift to 2nd or 3rd

[IndyRich]

Edit....Thanks to all who helped. I finally got around to messing with it and it was THE GOVERNOR!! Teeth stripped to nothing. A new Sonnax one $44 shipped to me,beats a rebuild


Hi everyone, so I'm driving home from Lowes and as I accelerate from a stoplight my truck (tranny) won't go fast than 25mph. It takes off like normal and then just revs higher when I hit 25mph and won't shift to 2nd or 3rd. I limped home and checked reverse, it works fine. No vacuum lines came off, fluid level was a little low so I added some, but that did not fix it. Would love to hear your input!
Questions:
1. What does the fact that 1st and reverse work mean? what can I eliminate because of that?
2. Some very small debris in fluid, what does that indicate?
3. If I pulled it to have it rebuilt, what is a "good" price for a TH400 rebuild?

Thanks in advance!
Rich