Application pool but be restarted in order for page to load

The issue seems to be placed on the shoulders of application pool.  My site won't load on more than one client until application pool is restarted (recycle doesn't seem to do anything). As soon as one client one client has received the website application pool must be restarted if another client wishes to load the site. This also effects switching between pages as only one client is able to do this until application pool is restarted so another client may as well.

I'm also not overly familiar with application pool and how it works so i end up using the default settings which seems to work for a few days until suddenly it doesn't.