Oh man, I feel exactly the same way. Even if it is something I actually like, just getting started can be so hard.

My only real trick is to try and do something for ten minutes and then I can continue or not as I want. Often I want to continue, sometimes so much I get irrationally angry on the timer because it interrupts my work.

Do you have any other strategies?

The catalyst should also be specific. A smartphone is a very broad-spectrum catalyst that accelerates all kinds of side reactions, depleting your free energy.

You want to have specific catalysts (think enzymes), clean feedstocks, and a good supply of free energy. Also the pressure (physical/mental confinement within one area) and temperature (level of stress/energy/chaos) need to be managed.

Yes, momentum is key. Without it, every little thing seems hard.