Well, if I had better theories on creativity, I'd be a more productive artist myself.
A joe-job doesn't leave you much you-time or energy for personal expression, but I think you can compensate with sleep hygiene, organising your day, and the right drugs.
And you should go back to whatever inspired you in the first place, and binge on it, find out who your favourite artists' favourite artists are and binge on THEM.
As "Bob" said, "Do What Keepeth Thou from Wilting, Shall be The Loophole in the Law".
If you get yourself in the right headspace, you build up power during the workday, like a capacitor, and release it when you get home, and then bam, art.

a lot of the things that inspired me in the first place are gone or changed :/

That's why you gotta deep-dive to explore up and down the tree of influence, the progenitors and derivatives.
https://www.deviantart.com/fox-oria.....late-174550753
This might help you get your groove back.

Sometimes you can’t wait for inspiration and you have to force it and hope that either you like what you make, or it gives you the go to make something you will. If I’m not on discord you can message me and I’ll respond when I can.