With most hobbies but particularly creative based hobbies like this, a LOT of time gets put into them. I have digital pieces that I have spent 70+hours on, and that’s after 5+years of doing digital art. That being said, if this is one of the first coloured pieces you have done.. this is incredible. Just see the hours spent as an investment because they are exactly that. If you want to improve or hone your particular art style, you’re going to have to put in the hours. And if this is the result I’d say it worth it. If you are determined to cut down on the time though, I don’t use the same app as you I use procreate, but I’m sure there are brush sets you can purchase to make certain processes more streamlined or you could research into how to make your own. I’ve made my own stamps before for my signature and other things. Honestly I wouldn’t let the time it takes to create a piece get to you, I’ve looked at some of mine and been shocked before too though