The answer to the question if it is allowed is readily found in the help center:
Can I answer my own question?
The short version of the answer given there is: "Yes!" On top of that the software explicitly supports self-answering.
The more relevant question should be how this will be received. It is said in OP "[...]I think this question helps others."
Somebody else might simply disagree with that judgement and react accordingly. And, I feel it is reasonable to impose somewhat higher standards when judging usefulness of self-answered questions.
The rational being: if somebody asks a question that they actually have, in the sense of they want an answer to it, then essentially by definition the question is very useful to them and it is hard to argue with that. So, in the standard scenario there is at least one person for whom it is definitely useful, which makes the threshold for deciding the question is still not useful quite a bit higher.
In a self-answered scenario this is not the case.
Briefly and roughly: I feel in the standard scenario the burden of proof should be with those that think something is not useful. By contrast, in a self-answered scenario the burden of proof of usefullness is with the one posting.