Disavow your own domain

Has anyone tried disavowing your own domain? Does this work? Does it have a negative effect?

I just saw in my disavow file that I had accidentally included the URL to my startpage in my disavow file. I’ve had huge ranking issues the past few months. Nothing I tried had any effect at all (and I tried everything) and by the feel of things it felt like my site was penalized and wouldn’t budge in the ranks regardless of what I did

By accident I looked through my disavow file today and to my surprise, the URL to my startpage was included there accidentally.

Removed it and recrawled my site, yet to see an impact but now wondering - could this genuinely have had a negative impact? Shouldn’t Google be smart enough to know that you wouldn’t actually want to disavow your own startpage? What would such a disavow even mean? All outgoing links from your startpage to the rest of your page ignored?

Interested to hear takes on this, if this could have negatively impacted my site or if I’m just being wishful in hoping so?

My startpage shouldn’t be in the disavow file so removing it is good, but could removing it also have a positive impact? Love thoughts on this
Thank you!