It's difficult to say what "decent comic" means. It can vary a good deal from one person to another.
Your art still has a long way to go before it could be considered professional level, but that doesn't mean you shouldn't make a comic. It's clear that you love drawing and that you've likely been learning, practicing, and getting better with time. And making a comic is one of the best ways to continue learning and pushing your skills. (I still have a long way to go, too, but making a comic has made my art significantly better over the 5 years I've been running it. Being forced to draw characters in different angles, poses, and expressions over and over again will sort of FORCE you to improve, especially if you push yourself to try things that challenge your current skill level.)
If you're worried about whether your skills aren't good enough to make a "great" comic, then maybe start with making a less ambitious one as "good" as you can for now and use it to practice.
Best of luck and I hope you keep creating cool stuff!