You can only do what motivation drives you to do.
But the thing is, you can do something quite meta, which is to hack your motivation in order for it to motivate yourself into doing something you lack motivation by default.
There are several ways to achieve this with your mind.
- Lessen the demotivation: Optimize for less aversion, which means that the small motivation that you will have will more easily flourish into you doing the things you want to be motivated to do.
- Do little by little: Like a scientist, analyze each step of the way. Dissect every task into smaller subtasks.