So you are bored and your job has lost its luster. For that do something completely different and do it just for fun. If you work as X and even if you are good at X you will eventually get bored of X. Imagine if you had ice-cream or chocolate all the time. Eventually you will hate eating anymore of it. The thing is to do something you like or you feel you need but do it only for yourself and not because you have or need to.

Stand in front of the mirror and ask yourself what you like to do. I, for example, started exercising more after trying it and stopping because of life matters. Choose something that you like and make you feel you're experiencing a new thing. Don't learn another programming language like everyone on HN is suggesting. You know that saying about when you're a hammer...

Just because you are good at something doesn't mean that it's enough to fulfill you. It will make you proud of yourself for a while but then it'll start wearing off. You need something that makes you feel in touch with your purely human nature that is different from your daily job. How about painting, cooking, exercising, stamp collection (a dying hobby), reading poetry (I won't do that but you might), theater, dancing lessons, gardening, sightseeing, photography, magic tricks. Don't pick something like your job.