Don't get stuck, get moving.
Sometimes, we get to a point where we feel we've run out of ideas or motivation, or simply not having a solution to a problem. This is where most people get stuck in a loop. If you find yourself dealing with this scenario, get moving. Get on to the next thing on your milestone. When you do this, oftentimes, I have found that you are more likely to discover the solution to the issues you left unresolved. Progress in one thing has a way of inspiring progress in other things.