Increased workload - how to get another person recruited?

[solo2]

Hi,

As title says, I've been in my role a little over 3 years and have seen the workload drastically increase to the point where I am often logged in up to midnight most workdays and often one day a weekend just to keep it ticking over but by no means on top of it.

My employer is good and I am certain they would accommodate a part time or even full time role to work alongside me but the first thing they would ask for is details of why and this is where I come unstuck. I've never been that good at describing what I do, and how long it takes me. I can say with all honesty I spend 90% of my day answering emails but when I try to quantify exactly why it takes that long, I cannot. And then I spend so much time keeping on top of emails that the actual work is not getting done. There are potential late fines to be applied to the company if I do not keep on top of it - nothing huge but if everything is running as it should then there wouldn't be any. I just literally have more than I can do even with spreadsheets that take a lot of the work off me by means of v-look up etc etc.

Any ideas on a format to present to Management so they will seriously look to recruit before I have a breakdown. I love my job, I do not want to leave and I really like the company, only I have just been a bit too good at what I do and grown the role more than I can do.