Not surprisingly, where you are can affect how you are. I'm currently taking advantage of this by spending a couple of weeks working in temporary office accommodation ten minutes' walk from home, and it's remarkable how much difference a change of environment can make. In my case it came about because I've a big chunk of work which requires complete concentration. Although I'm perfectly well set up to work at home, it's great to set off for an office every morning - and of course it's healthy to be leaving the work behind every evening (as you may have found yourself, the lines of demarcation may get blurred when you work from home).
I'm fortunate, of course. Not everyone can choose to work where they wish. But you could apply the same approach to just about anything you need to do. For instance, say you've a daunting pile of household bills to process. Why not sit at a different table from the one you usually do, and in a different room? Or how about packing up the papers in a bag and heading for the local library for an hour? Do the dull paperwork there. Remaining in the same physical place can often mean feeling the same way, so why not perk yourself up by parking somewhere different?