Overdrive and speedometer aren't working! Please help
 

Hey guys, I have a 97 Eldorado and earlier today I noticed that it wasn't shifting into overdrive and my speedometer was jumping between 0-45mph. I checked all the fuses under the hood and in the trunk and even checked the fluid level, any other ideas of what it could be? I'm a decent mechanic but this one has me stumped. Thank you!

I forgot to mention, when I threw it in neutral it seemed like it downshifted before it hit neutral and when I put it back in drive it stayed in neutral until I started pushing on the throttle.