thin and slim may mean the same thing but they are not synonyms. 'Slim' largely means being in a good shape not with big muscles or fats. The body is not broad or bulky. Actually a slim person is thin but attractive.
On the other hand, 'thin' refers to a person who looks thinner than she should be to look attractive. slim is more positive than thin. 'Slim' could be appreciating someone.
If your friends say that you are 'thin', they probably care for you and want you to put on some weight.
These days, looking 'slim' is on the rage. So, if you meet a celebrity, calling her 'slim' pleases her; calling her 'thin' may make her face frown!
I'll suggest not to use 'too'. Instead, simply say ...
You look 'thin'
In case of 'too thin', say...
You look 'very thin'
There's one more word - skinny; but use it with caution!
There are two reasons.
First, "it never exist" is never grammatical: you mean "it never exists".
The second is much more subtle. "Don't tell me it never exists" is grammatical, but is not something an English speaker is likely to say.
I am struggling to explain why this is, but I think the answer is something like this:
"This exists" is not usually a property that can come and go: a thing either exists (or doesn't) for all time, (qualities, for example), or comes into existence at some time, and continues to exist until it no longer does (people, for example).
To negate that, we usually say "doesn't exist". "Never exists" sounds odd, and to me it would imply that we are talking about some odd kind of thing that sometimes exists and sometimes doesn't, and we are saying that this particular thing never does.
An example (somewhat contrived): The King (of a particular country) is something that can exist at some times but not at others. So at present there is a King of Spain, but no King of the United Kingdom.
In that context, I can imagine somebody saying "The King of Spain exists, the King of the UK doesn't exist, and the King of the United States never exists". (It's not a likely thing to say, but it makes sense, sort of).
With a past tense, "never" is slightly different. To say something "never existed" is not unusual - it means that it doesn't exist now, and never has; but it does not have that implication of something that might come and go.
So in summary: "Don't tell me that it never exists" would be grammatical, but unusual, and would imply that "it" was in principle something that could exist and not exist at different times. "Don't tell me that it never existed" would be normal, and not imply that the thing could come and go.
Best Answer
To express the results that are already existing, use: (the) existing results.
The word exist is an intransitive verb, so we don't use it in the passive voice, and we also don't use existed as an adjective. This rules out existed.
Both existing and existent could be used with something that exists, to refer to the state of existing (or existence). However, existent would evoke the sense of existence which is related to philosophy and life in general. So, I believe that the word you are looking for is existing (for your existing results).