I have always worked from home, from graduating, even without covid - for almost 10 years now. It is difficult, and there are challenges (particularly if you're used to not working from home) but you can overcome them.
A specific work area and desk is a must, then you can 'leave work' at the end of the day. Preferably in a room you don't chill out in, but I appreciate that's not always possible.
Set strict times for when you do and don't work.
Get out every day for a walk, to do some shopping - anything. I find even a walk round the block clears my head a little.
Make sure you're socialising - so meet a friend/family member for a walk/coffee, or go and visit someone. If you have friends who you'd normally work with, keep in touch with them if you can.
It's not easy, particularly for those not used to it, but there are definitely ways to make it better.
Also, this is THE worst time of year to work from home. It's much better in the summer when you can set up outside, for example - so if you're still WFH when the weather improves, definitely try to do this!