If you really like to follow an order, perhaps you can create your own and ignore the opus numbers. So order the Beethoven Sonatas in the order in which would like to learn them; easiest to hardest, most appealing to least appealing, or whatever interests you. Then write down that order, maybe even keep it on a spread sheet. Then do the same for other composers you like. Then tell yourself you'll do one Beethoven, then one Bach, then one Brahms, or whatever, in order from your lists. Make it as disciplined and systematic as whatever OCD you have tells you to. Just don't base it on Opus number. This way you'll en up doing pretty much what you find most interesting, but you'll do it in a organized, systematic way that you find natural.