high load caused by buddypress activity plus

Hi guys, I've been using this plugin for a long time, without issue. However, today my site is running really slow. Long story short, my memory is maxing out and I've got really high cpu usage.

My webhosts have said the issue is with BP Activity Plus in that I have over 70,000 files. Their support have said that the directory ../uploads/bpfb/ should be split into smaller directories with no more than 1000 files in each. Basically they have said that older files need to be archived...

My site is pretty busy. Please can somebody help me with this, as I'm at a loss here...

Many thanks
Rob.