The most effective way to beat her is to play defensive. From what I saw, you tried to go against Peach head-on, don't do that cuz her priority is too high against Doc, plus when you get close to her, she ends up D-Smashing you.
Also you tend to spam F-airs a lot, which is good, but you may want to use that as a finisher/punisher/combo ender against a Peach (I'd say go for D-Throw -> F-air).
- I've noticed when you try to edge hog Peach, you tend to ledge hop and try to U-air or B-air her. All you have to do is roll dodge off when Peach is near the ledge and you would have gotten a quicker KO. And if you're worried about her getting a second jump in, remember this, several B-airs will lose her 2nd jump.
- You tend to spam attacks in general hoping for a good hit, don't do that, or else you're going to get punished like you did in the video.
-Catch turnips! Cape Turnips! You got the tools to use those against her. Whenever I play against Peach I always cape those turnips. It screws up Peach's game so much it's not even funny.
-Do not ever try to hit Peach underneath a platform while she is doing her D-Smash, you will take the damage as if you're Crouch Canceling it. Go for a U-air after she is done with the attack and combo her to a B-air or F-air.
-The only attack imo that will battle against Peach's speed/priority is your B-air. SHBAWD (Short Hop Back Air Wave Dash) those against her. U-air and N-air works pretty well against her.
-Get a little more practice on Wall-Teching. Wavedash more and roll-dodge less.
Other than that you're definitely not a n00b, so just keep on working with the stuff above and you'll do much better against Peach.