How do you adapt to the situation? Did you have to stop something or you found a way to carry on?

As during last dozen years or so I relocated quite often internationally, I was already used to play on PbP, rather than face to face (that is always the best option, in my opinion, if you manage to overcome the practical hurdles of distances and times), so for me it wasn't a big change.
However, Covid-19 impacted many lives in many ways, and some of the players of campaigns I am running are healthcare workers busy on the front line, so they don't have much time available, but, when they want to isolate themselves from the harsh reality, they enjoy playing RPG games on PbP, as it helps them focussing on something different. For this reason, I have been running more solo games, as their posting is more erratic, but, when they post, they are keen of seeing the story progress. I tried to do my best to support them this way.
Other players actually caught the virus, so it was a pleasure, after a break due to sickness, seeing them coming back to the game, slowly at first, and then more and more frequently, as their strengths came back.
It was good also for me, especially during the times with the most restrictive lockdown measures, to fly away with my mind from the current situation, as I was often feeling like a tiger in a cage.

With hindsight, I have to say that I keep playing and running games (all at distance), but I have big issues with my creativity. Am I the only one struggling much more than usual to write anything new and decent?

Strangely, No.

I played almost 100% online on roll20 before the pan so it shouldn't have many any difference.

But it did. I am totally unmotivated to run anything and have not played anything since it started.

Every once in a while I get up a moment of motivation but it fades before I can finish preparing.

My players are either feeling the same way or beyond confused as to why our gaming suddenly stopped.