Help with feeling exhausted on days off from gym

[OpenToSuggestions]

Hey all.
I am a gym goer and enjoy lifting weights. I'm not a pro nor am I aiming to be huge, but it keeps the weight off and I have grown muscle.

History:
Oct 2013 - Decided I was too fat. Did cardio.
Feb 2014 - Started doing weights. Was training with others but was NOT eating right at all!
May 2014 - Changed gym to a cheaper yet better one nearer home. Train alone 95% of the time. Diet gone from poor to average.

I sometimes take protein shakes, but to give you an idea of how often...I am on the same 5KG bag that I bought in August!
I regularly take C4 pre-workout.
As of two weeks ago I have some BCAA.

My problem is that I enjoy going and it clears my head, but I get SO tired come the weekend. Yesterday I just slept all afternoon!
In the week I get around 7-8 hours sleep per night. I am often flagging on my last visit of the week.

Routine:
Day 1 - Chest and Triceps
Day 2 - Shoulders and Abs
Day 3 - Back and Biceps*
Day 4 - Legs

*Biceps and back often split into different days if I feel like going 5 times in the week.

I realise this has been a long one and that I have probably missed some details out!
I really can't stop going. i have always eaten a lot and this is the only thing in the last 10 years that has kept the weight off.

 

[OpenToSuggestions]

I'm not mr socialable so whilst I am always on the go I don't mind catching up sleep at weekends.

I am thinking my diet is the killer here. I seem to be always eating...but not from the right sources.

 

[OpenToSuggestions]

Hey all.
Bit of an update.
Upped sleep during the week and it has made me feel much better.

I never would have thought just half an hour extra per night would have this much of an effect!
My eating is still not where it should be, but baby steps!