All our knowledge of the world depends on perceptions. Every perception includes the feeling that we are geting a representation of a real world. Do I have any reason to doubt it? In specific cases, yes. As a general rule, no. Subjectivism is a metaphysical (unjustified) position.
Perception
1.
the ability to see, hear, or become aware of something through the senses.
"the normal limits to human perception"
2.
the way in which something is regarded, understood, or interpreted.
"Hollywood's perception of the tastes of the American public"
You are using perception in both senses without realizing that they are different.
"A real world" is not known through the ability to see, hear, or become aware of something through the senses.
You are using a positivistic rule for "real world", the problem is that your rule is as reality goes: "the state of things as they actually exist, as opposed to an idealistic or notional idea of them" is itself an idealistic or notional idea.
Your rule is a case of subjectivism,which denies subjectivism.
Your problem is that "subjectivism is a metaphysical (unjustified) position" is itself a metaphysical position and that unjustified is subjective and dependent on your own rule, which is metaphysical.
Something is metaphysical, if it can't be known through observation, yet is known.
You know "subjectivism is a metaphysical (unjustified) position", because if you didn't, you couldn't talk about it, but you don't know it through physical observation.
You know it, because you think it. I think differently about the words "real world" and I use a different rule. And that is real.
...
Austin highlights the complexities proper to the uses of ‘real’ by observing that it is (i) a substantive-hungry word that often plays the role of (ii) adjuster-word, a word by means of which “other words are adjusted to meet the innumerable and unforeseeable demands of world upon language” (Austin 1962a, 73). Like ‘good,’ it is (iii) a dimension-word, that is, “the most general and comprehensive term in a whole group of terms of the same kind, terms that fulfil the same function” (Austin 1962a, 71): that is, ‘true,’ ‘proper,’ ‘genuine,’ ‘live,’ ‘natural,’ ‘authentic,’ as opposed to terms such as ‘Real,’ is also (iv) a word whose negative use “wears the trousers” (a trouser-word) (Austin 1962a, 70). ...
https://www.iep.utm.edu/austin/
The problem is that unjustified is a negative as ‘false,’ ‘artificial,’ ‘fake,’ ‘bogus,’ ‘synthetic,’ ‘toy,’ but also to nouns like ‘dream,’ ‘illusion,’ ‘mirage,’ ‘hallucination’, but it is real otherwise you couldn't use it.
"‘Real,’ is also (iv) a word whose negative use “wears the trousers” (a trouser-word)" is also the case of your use of "real world" - the real world is defined by what the non-real world is, i.e. "subjectivism is a metaphysical (unjustified) position". Your problem is that this is only real, because you think it. I.e. it is case of subjectivism.
I suggest you practice metacognition. Not that you need it to have a life, but that you need it if you want to say what reality really is.