How to cope?

I'm pretty sure my husband has ADHD. We've been together for 20 years, but sometimes I'm wanting to throw in the towel. He doesn't even realise it. 

I work full time because he was wanting to start his own business, I'm also full time at university and apart from that I have to deal with all the chores, bills etc.

I'm so tired all the time, but it's worse when he has an emotional outburst because he can't cope when the house isn't as tidy as he wants it to be and he doesn't seem to understand that I have a lot on my plate.

He is in the waiting list to see a professional, but it's already been a whole year since I mentioned it. 

Any tips?