My thoughts are this is a fairly simple problem with an easy fix.
1) Fact thay you are hurting on easy days is a good sign. Your hard days are sufficiently hard. This is a good sign. Recovery days dont make you faster, your workouts do.
2) Easy days arent actually supposed to feel easy. Yoi have hard days and recovery days. You are hurting because you ran a hard workout the day before. If you are feeling comfortable on your "easy" days that means you arent doing your workouts properly. That being said, generally if you are in base building phase then you shouldnt be having this problem at all and most days should be comfortable.
3) You need to speed up recovery, thats all. If you get in better shape this will happen quicker, but right now you are not there.
Suggestions to speed up.recovery so your recovery days arent as painful:
1) SLEEP more
2) Eat really well after your workouts. Protein shake, meat, carbs, veggies. Watch your diet on your recovery days. On workout days, splurge.
3) Ice bath your legs or at least spray them with cold water asap after youre done cooling down and stretching.
4) Wear calf compresspr socks when you sleep and consider elevating your feet on a pillow.