It’s been doing this for years but this is the worst.
That's a problem my man. I'm no doctor, so serious caveat there, but my initial assumption is this is a fungal infection given its appearance and how long it's lasted. If that's what it is, you're going to have to get some kind of antifungal cream to treat it.
Again, I'm absolutely not a doctor. There are a couple over the counter antifungals you could try: Lotrimin, Neosporin, Tinactin, and Lamisil. I recommend you read about each beforehand.
Whenever you take a shower, wash it very gently with an unscented, mild soap like this one, and make sure your belly button is 100% dry before doing anything else. No creams, no clothes until that belly button is as dry as Ben Shapiro's wife. Get a hair dryer, it'll make it faster and help you know it's fully dry. Consider trimming off all your hair in that spot right now to help it dry faster. Any lingering moisture is going to perpetuate the issue.
Once your belly button is completely dry, then you apply the antifungal cream.
All this said, maybe it'd be prudent to visit an urgent care about this. Urgent care fees tend to be pretty affordable. Maybe see if you can get a quote ahead of time for one. It's likely that if this is a fungal infection, an OTC cream won't be strong enough, and you'll need a prescription like ketoconazole. The prescription itself probably won't be very much, because these creams tend to be pretty cheap.
I REPEAT YOUR BELLY BUTTON MUST BE SO DRY THAT BEN SHAPIRO WOULD MARRY IT. Probably nothing will work if you don't fully dry it after every shower and don't let it stay sweaty for too long. Do you tend to have a moist belly button? If so, Ben Shapiro would not like it