I know this is easier said than done, but you need to set time limits. Allot 30 minutes for laundry, 30 minutes for kitchen cleanup, 30 minutes for workout, 30 minutes for reading to kids, 30 minutes for cleaning out a drawer or sorting toys for Goodwill, etc etc. In reality, to complete ALL the laundry it may take an hour, sorting through all the toys might take 3 hours, and there is absolutely no way to get through ALL the jobs completely in 1 day. So just tackle a little bit at a time. Set a timer and once you have been folding laundry for the allotted time, move on to the next task. Don't forget to schedule in time for yourself; if you don't add "me time" or "workout" time to your schedule, it won't get done.
I am a bit of a compulsive cleaner and like things to be very neat and organized. But I do recognize that sometimes the time I am spending cleaning is at the expense of my kids and that time would be better spent doing something fun with them. It helps me to remember that even if I get the house spotless, it will be right back to messy within an hour.
Also I would suggest enlisting your 8 year old to help with many of the jobs. When my kids get home from school, it is "clean up time" and they get a list of about 5 jobs, generally putting away all their laundry, emptying wastebaskets, taking out the trash, putting away silverware, cleaning rooms, tidying bathrooms, etc. It teaches them responsibility and helps me immensely. Then we move on to homework and then we can have play time.
Also, it sounds like you are dreading summer and I just wanted to mention that getting out of the house as much as possible in the summer will help. The less time you are at the house, the less mess that can be made there! :) Try to get to the park, the pool, go on walks, go visit Grandma, have fun. I promise it will help!