Losing Data & Slow Performance

Hi, just recently my Smartsheet is going really slow, and I'm losing information I've just entered. I can't drag information from one cell to another, and can take 3 seconds or longer to load information, and half the time the file doesn't actually attach. I have to close down and reopen Smartsheet all the time so it saves my data. It's also going very slowly! I run it through Chrome, don't have other windows besides emails open at the same time. Have done the standard trouble shooting and logged a help job with Smartsheet but still waiting to hear back a week  later. Just really stuck as all my work I'm doing keeps getting lost. Anyone have any advice?? Thanks