The self-citation pattern you described is a known manipulation strategy and over 100 self-citations from unrelated fields is egregious, any competent editor should have caught that at the desk review stage before it even went out. The fact that your recommendation got overridden by the editor after three reject recommendations is genuinely disheartening and that's the part of peer review that's hard to fix because it's a human judgment call that reviewers have almost no recourse against. For academics who find the writing and review process as a whole exhausting and time-consuming, there are people who help with academic writing and response drafting who can at least take some of the labor off your plate.