Wow! That's strange it would do that sheila0713. Have you tested an alternate SD card to see if it's just this one that's causing this? Another thing you could try would be formatting the SD card using another device. It would clear everything off of the card, but if you're able to connected to a computer, it may be possible to save files like photos before you format it.
There are several possibilities. One is that you have apps on your sd card, and the new OS is unable, for whatever reason to complete updating them. Number two is that the sd card has become corrupt. It happens and nothing will screw up your phones performance faster than a corrupt card.
First, take the sd card from the phone, put it in an adapter and copy everything off of it to your computer. That way you will not lose anything.
Second, I would very much suggest that assuming that you can get the material off the sd card, that you reformat the card. Once that is done, if all is well you can copy your material back. If the computer cannot do so, or it continues to not work after the reformat, then get a new card.
Third, I would suggest you factory reset the phone. MAKE SURE you copy off whatever content is on the phone before you do this (pics, music, etc.) As long as your contacts are backed up in your google or Microsoft, etc. account, they will come back once you log back into the phone following the reformat. Many times, following an update, something gets messed up and the best course of action is a factory reset so you are starting fresh.
Don't forget to back up everything