Alright i know this is not the best way to make pixel art
All technical discussions aside, this isn't pixelart. This is resized CG and the involved techniques are very different.
I suggest you redo it completely, and when you do, there are some basic issues that need to be resolved.
There's a lot of difficult shapes involved in the cathedral, and it just isn't possible to wing it, if you want it to be remotely correct ISO wise. You need to spend more time doing the basic shapes.
If you take your standard ISO base square, it's twice as broad as it is high. If your doing a circle - same thing applies, twice as broad as high. This is basic yet important knowledge, that comes in handy when you do stuff like this.
What you got here is basically a lot! of circles (and a few squares), and because you haven't spent time on the fundamentals, none of them are "correct".
This is a quick demonstration of the problems as well as a suggestion on how to get it right.
Pretty much everything here are based on circles. The standard spires consists of circles on top of each other, and the same goes for the boubly ones.
Since none of them have them correct 1:2 ratio it comes of wrong.
Personally I prefer starting out with squares since they're are easy, and go build the (more tricky) circles based on this. This ensures correct ISO perspective and will save you a lot of time in the end.
Hope this helps.
If you however don't plan to edit the cathedral I suggest you remove it, since it isn't pixelart.
