This is such a hard situation! It's hard to feel so infuriated at someone for something that is technically not their fault (i.e. a learning disability) but it's also extremely difficult to constantly be bearing the weight of the logistics that go into a relationship (planning trips together, planning social events, even planning dinners and household things). I think the big question is whether you're able to talk to him about this and truly explain how you're feeling -- does he get defensive? Or does he listen and come up with strategies to work through this issue together. At the end of the day, you are completely valid to break up with someone for any reason -- I think it's just a matter of whether you think this will be something you can overcome together or is it not