A failure can only be defined by external factors, because a human isn't born believing one thing is an achievement whilst the other is a failure. That is all taught. Which means that none of what you say if we remove it from the context you are putting it in is true.
You mention intellectual disabilities, I have them too, that does not make you a failure, having a setback sucks but only because society wasn't made for people like us, not because what we have is something inherently bad. Have you ever gone up stairs, saw no ramp and realized a person on a wheelchair could not go up? Is that a failure on the wheelchair users part or societys?
You mention being ugly and having physical deformities. What do you define as ugly? Whatever you thought just now as a definition for ugly was soemthing ingrained onto you by growing up under a capitalist patriarchal society. Ugliness is subjective, or it should be, unfortunately most people are sheep and do not realize how their definition of ugly or attractive is not theirs. An example would be how in Japan Yaeba is considered cute whilst in the USA if your teeth looked like that you would be called ugly. All this to say you aren't ugly and your physical deformities don't make you so but I know loving ourselves is hard. Tho, you don't have to, practice body neutrality. We all have a body we have to live with. Why are you letting other people control it?
About boyfriends, why base wether you are a failure or not on the fact that you have a partner? Yet again you are just parroting patriarchal ideas. And who says he will leave you? And if he does what's stopping you from getting another? None of this is indicative of failure in any way shape or form.
Succeed in school well, I'm sure you know what I'll say, also no an indicative of failure. If you are in the USA you know they want to end standardize testing because it's not a good indicative of anything. And yet, I bet you would think yourself a failure for failing on a standard test. As it stands school doesn't work for everyone. Their methods of teaching aren't for everyone (even if Montessori adepts will tell you their method works on everyone). A lot of people fail in school, and yet they go on with their lives because it does not matter. Not for while school is the mess that it is.