What is a real recovery day?

You should have a minimum of 1 recovery/rest day per week. I honestly think 2-3 is more appropriate, especially for harder routines. If you are only having 1 rest day per week, I recommend it be a completely rest day. No exercise at all. Let your body completely recover from all the strain you are putting it under throughout the week.

Don't change your caloric intake on rest days. If you do then you risk fatiguing yourself the next day because you didn't get enough calories the day before. Your body still needs to repair and refuel. Which means it still needs that higher caloric intake. So don't change your calories. Keep them consistent.

Whether or not you are doing too much is only a question you can answer for yourself. How do you feel? If you feel burned out and exhausted then you probably are doing too much for your current ability level. If you don't feel challenged in your workouts well then you should kick it up a notch.

Signs of over training:

-Can't sleep

-Cranky

-Exhausted

-Developing injury or nagging pains

-Consistant fatigue

-A drop in fitness level

You just say you are "lifting" at the gym. You don't say what you are doing on those days. So we can't really help you with your muscle mass gains questions. However I do recommend only doing certain muscle groups on certain days. Don't do fully body workouts all days throughout the week. That will not lead to mass gains since you are not allowing proper recovery at all. I recommend doing something like chest and back one day, then you don't work chest and back again until the next week. This is what most weight lifters do. Recovery is absolutely necessary for muscle mass gains. So most people have 5-7 days of rest before working a muscle group again.

If you are a wreck by the end of the week like you are saying. I recommend having one complete rest day, where you do no exercise, and then another day of the week, cut out a cardio workout and just lift that day to give your body some recovery.

-Connor