How did you grow your upper chest?

I don’t have the greatest genetics but I swear my upper chest will just not grow even though I’ve tried so hard to force it to lmao.

The last couple months I stopped training my lower chest completely and pretty much only trained the upper chest (besides 3 sets/week of flat DB bench). Doing about 15-18 sets a week for my upper chest. Did it help? Maybe a little bit. Still pretty disproportionate though. I was doing flyes, incline smith machine bench, incline DB bench, converging press, etc.. barely any progress if any.

What can I do to make it more proportionate? My chest lowkey looks as saggy as a grandmas bro someone help me