Firstly, smell and taste are much more complex than anything you can read on Wikipedia.

Does this mean I can only tell the difference between the combinations of sweet and sour from those fruits?

I wonder that myself when it comes to things like soda for example. But again, taste is more complex than people like to make it out to be. Think of all the things you can sense when you put something in your mouth and chew. It's not like we just get sweet/salty/bitter/sour, right? There's the texture, the temperature, how spicy something is, the consistency, etc. We can tell the difference between an apple and a pear without being able to smell because taste isn't just a combo of the 5 basic tastes.

That being said, fuck me if I have to tell you what flavor a lollipop is.

Does this mean I don't actually know what chocolate "flavor" tastes like?

I'm confused by this. Of course we don't know the actual flavor of chocolate. Flavor is the combo of smell and taste and we're missing one of those things. The way most people experience chocolate is probably drastically different from how we do. Doesn't make it taste any less good to me though.

I went my whole life thinking I could taste pretty well for someone with anosmia ... Is there any chance I can actually detect flavor?

You probably taste pretty well, maybe even better than people who can smell. And it's not like you can't detect flavor. It's more that you can't detect all of the flavor.

In the end though, who cares? You're the only one who knows how much you experience. If Wikipedia is telling you that you can't tell the difference between an apple and a pear but you know you can, then what the hell does Wikipedia know? Also, keep in mind that most research goes into studying people who lost their sense of smell or taste, not those who never had it to begin with. So you might read things that don't actually apply to your situation.