Structure of a review paper with author's unpublished data
Let's talk about three kinds of papers that are commonly distinguished:

Empirical paper with original primary research
Conceptual paper with no empirical primary research
Review paper that synthesizes empirical and conceptual papers in the literature

Despite my simplistic categorization into three types of paper, this might be better considered a triangular spectrum and any actual paper falls closer or farther from any of the three points. All empirical papers have some conceptual development and some literature review; all conceptual papers have some literature review (but rarely any original empirical analysis); all literature reviews have some conceptual development (but rarely any original empirical analysis).
Your question seems to ask about if it is acceptable to write a review paper that, contrary to the norm, includes a little bit of original primary research. I have a two-sided response to offer you.
On one hand, in principle, if you consider paper genres as a spectrum, then you can do anything that you want that meaningfully advances your arguments. If the original research supports your reasoning, then it could be reasonable to include it.
On the other hand, there are risks when you deviate from established scholarly genres. I see at least two concerns with what you are proposing to do:

First, there is a concern about scholarly rigour. Presumably, almost all of the articles in your review are peer-reviewed. That is, they have been evaluated and approved by editorial committees with invited expert reviewers that are independent of the study authors. Thus, their reports should be given greater credibility. However, that is not the case of your original empirical research. It is your original work that has not passed scholarly peer review, yet you are offering it as evidence on par--or even with more weight--than published, peer-reviewed work. What you should do is to let your original empirical work pass peer review first before including it in a review of the literature. It is awkward mixing unscrutinized evidence (your original empirical work) with scrutinized work.
Second, I began with three common genres of work. The advantage of writing according to common genres is that peer-reviewers and editors know what to expect and know how to evaluate that kind of work. When you break from convention, you risk the high possibility that peer-reviewers and editors would not know how to properly evaluate your work. So, some might evaluate it as an empirical paper (where it would be considered far too light), whereas some might evaluate it as a review paper (where they would object to the original empirical work). You might be willing to take this risk, but you should not be surprised if peer-reviewers and editors have a hard time understanding what you are trying to do because of your break from convention.

Overall, I recommend one of two paths:

Do not include your empirical research in the review paper at all. If you say it only supports what the literature already says, then it adds little meaningful. In that case, it is not worth the risks of breaking from convention. But if your empirical research is substantial and meaningful, then you can submit it for peer review for publication as an independent article.
If you feel that the empirical research is not sufficient to be published as an independent article (or it is not worth your time trying to do that), yet it does add something meaningful to your review paper, then place it entirely in an appendix to the review paper. You are free to refer to it in the review as evidence, but the fact that you are placing it in an appendix meakes it clear that you do not give it the same weight as the independently peer reviewed work that you review.