[senko]

Separate your living space from your working space.

I started working from my home and after a few years of productivity and motivation sliding down, I'd spend entire day trying to motivate myself to work to only actually produce a couple of hours of useful work.

I rented a small office nearby that forced me to go out, walk a bit, and separate work from leisure. This has helped me tremendously. Ff there were coworking options nearby at that time, I'd use that - it has the added benefit of having other people around, which will motivate / inspire you.

Additionaly, try to end each day's work with a small, well defined task/thing - leave that bit for tomorrow. It'll be easier to start with, and it'll help you get rolling.

Excercise helps - but dont't try to attack several problems at once. Start gradually.