It is not only necessary to take breaks during the work day but also to disconnect once you leave the (home)office. Try not to think of work problems outside of working hours. Do sports, meet friends, play with the kids, whatever helps you to relax.
Also, try to get enough sleep. Most adults need seven to eight hours sleep per night to be fully productive the next day. Trust me, I know how it is to cope with sleep-deprivation, as a Mum of 2 I have been dealing with this for years. However, whenever they let you, try to get as much sleep as possible. If you have trouble disconnecting, you can try different things like yoga or mindfulness. There are also different natural products like RINGANAisi that can help you relax more easily.