Writing absolutely was easier when you were younger simply because you knew less of the craft. The more you learn increases the pressure to live up to your own knowledge base. You can see flaws in your work that you (probably) weren’t aware of before and this gives the false impression of creative back-sliding. This can be extremely discouraging and you may long for those early days when writing seemed so much easier. But that longing is rooted in a lie. Ignorance truly is bliss. So take pride in the fact that your struggles are the byproduct of improving your craft. Your work is not as bad as you think, you simply have a much stronger magnifying glass than you used to so the flaws seem bigger than they truly are.