I took your largest picture, then, I blew it up in a photo editor for the assessment you requested. Your somatype at present would be near a ecto/meso, if you are aware of somatyping. You asked what type you are. Even though MikePhil likes to generate controversy and "stir the pot" as he does, the assessment was accurate, and is not a put down unless you let Mike let you feel bad about yourself. I read your complete profile, as well as blew the picture up, BEFORE I made my call. Don't let Mike let you feel that you were somehow wronged. You weren't. You're skinny and lacking muscular development. 121#, at 5'7" (the only part of your profile you spent much time on) you are underweight by every standard that I'm aware of. You don't look toned nor athletic. You just look hungry. That's the truth, as I see it, and if that's the look you want, more power to you. Don't let the nut cases get you all worked up.
You really don't have muscle at such light weight, and without muscle, you really can't be toned, nor muscular. Muscular means an abundance of muscle, which you obviously do not have.
In your terms, from your original post, "slim" would be the closest.
You don't look like a swimmer (wide back and good overall tone). You don't look like a gymnast (good overall muscular development for height and weight using bodyweight resistance). You don't look very athletic because you are so small. You certainly aren't average because you don't carry enough weight. And, while you have a layer of fat (your body's protection mechanism for a low-calorie diet), you are not by any means "fat" / obese. Mostly, you just look hungry.
GG makes the point that it was a loaded question, and it was. You asked the question requesting for a classification / typing and then didn't like the honesty put forth. You can't have it both ways. Reality is what it is.
Point is there are always going to be nut cases like Mike Phil, or other folks that will get you worked up, but, what it gets down to is that you have come to like yourself. What you were actually likely seeking was validation, like...Oh, you look great, rather than a honest appraisal. Like someone asking "how are you today?" They don't really want to know how you are, and could give a shit, and you just answer back "I'm fine" when in fact you're having a shitty day. Don't ask a question if you can't live with a honest answer.
Bottom line: if you like being 121 at 5'7" then be 121# at 5'7". If you have inner strength, you won't care what anyone else thinks because it won't matter to you.
Guys like MikePhil lash out at others. They love stirring about emotion and getting into flame wars, name calling and the like, but, they don't cut to the heart of the question with integrity.
I get hate email because guys think I'm to big, but, because I like myself, mail like that, and nut cases like the MikePhils of the world just go in one ear and out the other. Once you have an inner confidence, they don't matter. They're just noise off in the background.
If getting built will give you confidence then do that. If being the way you are gives you confidence then do that. Do whatever makes you happy, and live your life for you. You wanna' be skinny, that's fine. You wanna' be big, that's fine.
Right now, you're real skinny and underweight. Just the scale, in and of itself tells us that, but...you knew that already. What you really wanted was to be propped up. That...you have to do from within. Come to like yourself, and the rest will follow. At that point you'll realize the MikePhils of the world are just noise off in the background, and don't really have much of value to contribute to your life. Live your life for you, and the rest will fall into place. Like yourself, and others will too...but, that doesn't mean that insecure folks will come flocking to you. They'll want you to be like them, because...they feel threatened by confidence and self-esteem. I assure you, coming to like yourself is the key.
If you're dealing with lupus, then, do whatever makes you happy. In the big picture, it really doesn't matter what others think. Ask 10 folks and you'll get 10 different answers, but, I try to ground my answers in logic.
I took time to be honest because I feel you are worthy and it's a disservice to answer your question falsely.