What type of transmission do i have

I have a question anyone that can help me I have a 96 Dodge 2500 360 automatic gas motor I cannot put it in park for about the last two weeks then one day it would not come out of low I drove it for a while and shut it off when its side of the store came out started it it drove fine for 2 weeks and I was going down the road and it skipped a little bit next thing you know it starts spinning really bad in gear and won't move I still had to reverse I shut off the truck I started it it drove for a few box went back to spending again I shut it off started it again for a few short blocks and got me home what do you think is wrong with my transmission I have the overdrive button on the dash could somebody please help me James in Florida

NV3500 @KDerrick 96