My sister worked full time and her Dh would often be called away at a second's notice due to the nature of his job so they couldn't plan around it. She would spend part of a weekend batch prepping foods whilst her Dh was around. There are a million youtube videos showing you how to do this on a large scale, how to get organised and then using a slow cooker on a timer to dump the evening meal in. The Batch Lady on youtube is good for variety there are others that prepare like 30 meals in one go. That might be overwhelming though.
She also used the delay timer on her washing machine so it was just finished as she came in the door and then she put it on to tumble dry. Her children helped with this from a young age. So loaded in the morning and it was presorted, ie no individual baskets but a central laundry system with whites, darks and lights. Toddlers can learn to put their clothes into these baskets. I had the same system with an additional school uniform - trousers and jumpers, polo shirts went into whites.
Set some new routines, you don't need to do a bath every night, again my sister did showers, quicker, no lingering and still clean.
If your Dh is home, tag team and divide and conquer. If you can throw some money at buying in help ie a cleaner once a week, you would be amazed what can get done in an hour with no interruptions from children.
If you aren't already making them, the children tidy every day, it should be part of your routine, we did this to music. Friday night we always did disco night, ie multi-coloured disco ball, music on request which helps tire them out 
Clothing wise honestly buy comfortable clothes, I don't care about label sizes just what fits and weight loss can come when you can.
It is hard when they are young and need you so much, it does get easier, be kind to yourself.