The information you are being given is coming from several different people, some whom have the right idea, but still aren't hitting the mark.
First things first. Stopping training six days in a row. The body needs rest. The body is a single whole unit, be it the musculoskeletal system or your nervous system. 2 days on, 1 day off can work well, with the weekend off, which equates to 4 days a week. In my personal opinion most people would benefit from 3 days a week training, with 4 days a week being good for certain programs and training splits.
Second, you can train the same muscle 2-3x a week no problem, but the key is that you have to have the right programming with regards to the weights used and the number of sets performed at each workout. The classic 5x5 programs in all their variations have you squatting 2-3x a week as a matter of course. The key is not taking sets to failure. Training to failure on an exercise IS NOT A PREREQUISITE for increasing strength or muscle size. This is an indisputable fact, and if anyone tries to tell you different, then they don't understand some basic concepts like GAS(General Adaptation Syndrome) and how linear progression or periodization work.
The best advice I can possibly give you is to pick up the two Mark Rippetoe books, Starting Strength and Practical Programming. Study those religiously and DO what they say. I've been all over the whole training spectrum from 6 days a week Arnold style training back in my highschool days, while simultaneously pushing every set to absolute momentary muscular failure, to Mike Mentzer style doing 1 workout every 3-5 days with only 3-4 actual sets. I can tell you unequivocally that training to failure is not the way to go and that most weightlifters, powerlifters, strongmen, and pro athletes do not train in this manner.
Taking a set to momentary muscular failure places tremendous and unnecessary demands on your central nervous system. Many times a person cannot make progress because they CNS is essentially burnt out or in a highly fatigued state. Whenever the goal is to improve at something, in this case we'll use the barbell squat, it is imperative to keep in mind some simple rules:
1. How much weight are you using and how heavy is it in relation to you right now, and in relation to an advanced lifter. A 115lbs set of squats will feel hard to you, but given proper loading and rest protocols this is not that big a deal for your system to recover from within 48 hours, yes, ONLY 48 hours, provided nutrition and sleep are in good order. On the otherhand, a 315lbs set of squats may be relatively light to an intermediate lifter, wherein they could practically squat that weight every single day without issue, provided the volume of reps was easily within their recuperative capacity.
2. How much volume are you doing? Too much volume overstresses the body to the point that it cannot recover and then supercompensate within a reasonable time frame. This is the problem with HIT style workouts that typically advocate training twice a week, or once only every 3-5 days, because they grind their CNS into the dirt with excessively taxing training to failure, not to mention the repeated curbstomping to the CNS by static holds and then slow negatives at the end of a set taken to failure. One of the biggest problems with this style of training is that for many people it does not provide adequate volume, which imho is essentially saying that for many people, 1 set does not impart enough muscular damage to guarantee optimal muscle growth. One must also compare the effect of training the same muscle group 2-3 times a week to once every 7-10 days. Which do you think will grow more? I know which one I'd choose. That's right, the one that occurs with greater frequency, PROVIDED that the intensity of the sets, the number of sets, and rest and nutrition are in proper order.
3. I kinda covered #3 in #2, which is frequency. Intensity, volume and frequency are the 3 main training parameters that every program needs to have in order for it to be optimal. Too much intensity utilizing training to failure makes it hard or impossible to progress unless your volume and frequency is greatly reduced. Too much volume provides too great a load to your system, which requires less frequency or lower intensity in the form of lighter weights. Despite what some people say, advanced lifters can and often do benefit from greater volume, but they control the intensity of the work and often expects gains to take longer. Your ability to recuperate from training improves as you get bigger and stronger over time, but your strength can and will exceed this recuperative increase, which is why intermediate and advanced lifters begin to expect strength gains once a week to once a month. A beginning lifter should be able to make progress from workout to workout in the form of at least 5lbs jumps for a good while. This could be a couple months to as long as a year.
I could go on, but if you get 8 or more hours of sleep a night you are doing it right.
If you use protein powders and all kinds of supplement while eating shitty foods you are doing it wrong. You are what you eat. Put good, clean, wholesome food into your body. Get rid of sugar and white flour products. Get off caffeine. You mention you have issues with energy levels. Well I wouldn't be surprised if you are in a state of overtraining caused by your training methodology and from use of stimulants and an excess of sugar in your diet. Many people don't realize that caffeine makes you tired. White sugar makes you tired. The combination is a great way to give you ups and downs throughout the day, and to generally make you feel like you are in a permanent state of fatigue.
So, to recap, buy the 2 books I mentioned. While you're at it, I would HIGHLY recommend you read the book, Nutrition and Physical Degeneration by Weston A. Price. I believe it's in the public domain now so you can download it from the Project Gutenberg site for free. Just so you know, I am in no way affiliated with the author's of these books. I just happen to believe that what they have to say is completely SPOT ON, and that they could benefit you greatly.