I'm watching the first game. Three stocks in, you have not pulled a turnip while fox is on the stage, and you have not dash attacked once. These are tools you must use to control foxes movement. You also get clobbered pretty bad once he hits you, and as far as I can tell, it's because you're a little hasty to counterattack once he knocks you away. At 4:05, you do the first attack of the entire game, which, interestingly enough, was the one time you should've done your fc nair pillar into grab.
I think you have a very common problem amongst peach mains, which is the tendency to respond to fox by doing something instead of nothing. When I watch your peach, it feels like you're always moving towards him, regardless of who won the last trade. If you get an opening, you chase it instead of going for stage control or positioning.
You try to take space using inappropriate tools: approaching with low FC nair instead of dash attacking, and expecting your aerials to win bad trades with fox. I saw you use groundfloat nair on wakeup, which would work, assuming he's gonna run in and grab you. He was reacting to your wakeup, though, but it was just within range of your dash attack. You need to make him respect that option.
I'm not gonna say you Dsmash too much because you're playing against fox, but a lot of your setups are ineffective and you throw it at some rather silly times. I do like seeing players utilize the fear attached to that move, but it's the same as dash attack- they only respect it if it works.
An example of my points thus far is at 7:00, your last stock of game 2. from the time that you respawn till the rock transformation, you are always on the right ledge, and he has enough center stage control to keep you there. He more or less pecks away at your attempted counterattacks and racks up a whole lot of damage, eventually forcing you off the ledge, where you sweetspot parasol.
(on a side note, this recovery is limited, and this is the point of the set where he begins to figure out how to trade bair with it. You needed to start sweetspotting it out of one of your prior options, but by continuing to do it, you let him further figure it out. Your recovery is good and flexible, but that doesn't mean you can do the same option every time.)
So you're on the ledge, trying to convert it into a kill, but we have to consider what that would require. First thing that comes to mind is a dsmash, which you realize, and do at every opportunity you get. Once you land it, you throw away your positioning, despite him jumping in on you by the ledge for the third or fourth time now. Had you stayed there, with a bit bit of wavedashing, you could bait a landing and get your dsmash or dash attack, putting him off or above the ledge. But you move to center stage to follow him instead. This moving towards is what I'm talking about- you doing something instead of waiting. And because you approach, he wins the trade (fsmashing your groundfloat nair, what I was talking about earlier.) Good **** winning that game, though.
Having watched it all, here's what I have to say:
I kept getting the feeling that you weren't utilizing dash attack to it's full extent in this matchup. You need to USE it. That doesn't mean throw it out at every given opportunity, but it's a tool at your disposal, and it's pretty effective vs fox. I attribute your lack of low percent grabs to your limited use of dash attack. You NEED to use both vs fox because of how they play into one another. You also chaingrabbed in a few situations where I would've dash attack -> uaired, but that's personal preference. He's a lot easier to deal with when he's on the ground, and both uthrow and dash attack achieve that.
Most of the time that he hits you after initiating your pressure, it's because he fullhops out of your fair-dsmash crossup. I'm an advocate of usmash in that situation; just do that instead of dsmashing. You took a lot of damage in this set in this spesific situation.
You lose a lot of trades because you try to use a lowfloat aerial, which you can't CC out of or react and punish. Floating is vulnerable and you need to think more about why you're doing it, or whether or not you're doing it safely. You do this at times when you should be baiting his approach. Hold your ground, run around and get ready to wd away and dsmash/dash attack/grab.