I'm the evil teacher who assigns the homework to kids, LOL. Actually, my students like me cuz I don't like to bog them down with too much homework especially on a daily basis.....they have several other classes to worry about as well.
With little kids, it's tough because they haven't fully developed independent work habits, so parents/teachers have to monitor them more closely and are more involved. As they grow older, they learn to do homework more independently with reduced monitoring.
When you run out of patience, take a break and get refreshed, get something to eat, refuel, etc. And maybe have your kids take a 5-10 minute breather also...and then come back to the task. We all need to step away sometimes.
I don't know if this would be a helpful strategy. I know some parents (mine used to do this as well) prepare their kids for upcoming lessons on the weekend. Let's say that a child is learning the 2's multiplication table during the week. Then you can review and teach him/her the 3's multiplication table over the weekend. That way he/she will be prepared for the dreaded 3's the following week....and in-class assignments plus homework will be done with more ease ;-) I'm not sure how relevant this tip is to your thread, but I hope it helps.
Since I don't have kids, I don't know what it feels like to be on the other end. I only dish the homework out:) But I think it's SUPER AWESOME that you're taking the time out to work with your kids, MashaAllah. Believe me, I've seen kids who struggle so much in school because parents are not and were not involved at all. The effort that parents put in when kids are younger.....pays off sooo much when they get into the upper/higher grades, and needless to say it's research-supported. So, way to go, Niksik!!!!!!!!!
Besides......getting tired......means you're doing an A+ job!!!!!!!!