My advise is to first go get your levels checked to see if it's a testosterone issue or something else. Due to your age, you're probably in the right direction, but it's still a guess. You're attempting to self medicate a problem that you really don't know what your body may actually need.
If you get yourself checked, you'll also have the ability to purchase pharm grade test which you know is dosed accurately. You may also save money in the process as well if you are insured. Sourcing UGL while some are going to be better than others, one roadblock is you actual dosing may not be accurate.
Your pinning intervals are probably accurate to what a doctor may prescribe. The steroid you're using, it's half life and your current regimen will run you on a roller coaster. You'll probably feel good for the first few days, as the Test E half life runs it's cycles you're more than likely feel a difference as your T levels diminish. I'd probably switch to injecting every week, that will keep your levels a bit more consistent. Once again, any of us will be guessing to what you actually need as you really should get a baseline blood test to see how low your T levels actually are. At the 12th day, you're going to be close to your baseline T level.
A more costly but effective consistent way to increase your T level (once again if this is your issue) would be to switch to a cream. Since this is a daily regimen, you won't have the high/low effects that is more typical using an prescribed injectable.
One other food for thought, when you first started administering the steroids, your body was releasing it's normal level of T. Initially, the addition of new T to your body, your levels were probably spiked quite a bit over normal. With the new additional testosterone you've added, your body quickly attempts to get back to it's predisposed levels. This means you're body will slowly reduce it's natural testosterone level (why your testicles atrophy).
SO now you're body T levels are going to be overall lower than when you initially started. To compensate for testicular loss, you can compensate with HCG. Again, before doing anything type of cycle, I'd get some blood work done so you can see your T levels.
Good luck!