Struggling with 2nd day of meets and several days after

Does anyone else have this problem, and if so, how do you manage it? Or is this just what I should expect from being 48 years old? Any feedback is welcome. During two day meets, I am finding that I swim really well the first day (usually two events, no relays), and then end up tanking the two second day events. I mean I am stiff, sore, tired, plain old worn out. This past week on the first day, I dropped 5 seconds ion the 200 BR from a month ago for an MPB and then .5 seconds in the 50 BR for close to an MPB. I was pleased and figured I would at LEAST drop a second in the 100 BR and 100 IM the second day – maybe as much as 2 seconds. Not even close…The 100 BR was the same as a month ago and the IM was actually 1.5 seconds slower. I mean I was out at the pace I wanted in both races, but when I went to the well, it was empty. So here I am 3 days after the meet, and I am still struggling. I took Monday off, Tuesday was a recovery day, and well, today was an even slower recovery day out of necessity – there was absolutely nothing there… I’ve been working a fairly structured program that includes swimming, strength training, and flexibility – 5 to 6 days a week, 4, 000 to 5,000 yards a day plus weights. It’s periodized as follows: 8 week endurance phase with progressive strength Currently in the last 2 weeks of a 6-week quality phase with power strength Up next is a 3-week race specific phase with 1or 2 weeks of strength maintenance Two week taper My warm up is usually between 1600 and 2000 yards and concludes with 3 or 4 x 50 at race pace on a long interval and then 4 x 25 sprints from a dive. Any ideas? Thanks, Glider