Exporting has slowed down please help!

I work on about 60 videos every month. These videos are all about 1 minute long product showcases on a turn table.

The average video takes about 5 minutes to export. I have 5 sequences created in one project, with different information, but they are all laid out exactly the same. They are essentially copies with different names depending which website i'm sending the video to.

Recently one of the sequences has been taking about an hour to export. I tried exporting through premier instead of doing it through Media encoder, but still takes about the same amount of time. During the export the file gets to about 48 seconds and my "RAM monitor" shoots up to 100% and my whole computer struggles and the encoder timer starts count up rather then down. I don't think this is an issue of having not enough RAM because this problem is very recent. I have done over 500 videos without a problem.

All of the other sequences are exporting just fine.

I even went back to an old video to try exporting and it is now running slow on that video also. Before the video exported with ease.

Does anyone have any ideas what could be causing this problem or ways to fix it?

Thanks

-Nick