The reason the gel didn't work is because all transdermal testosterones have a minimum 20% fail rate, even androgel the most commonly prescribed transdermal testosterone. For the other 80% of men, there is then the issue of transdermal fatigue they have to contend with, which means the gel/cream no longer works. There levels are still suppressed due to exogenous testosterone being introduced, but their body is not processing it. This is a very common problem for many men.

Injections, more than likely the issue you're dealing with is simply a roller coaster of up and down levels. Testosterone Cypionate and Testosterone Enanthate, the two most commonly prescribed testosterone compounds, both will yield peak levels 48-72hrs after an injection. From there levels begin to fall. How fast depends on how fast the individual metabolizes the hormone. Most all men will need one injection per week to keep levels elevated but hyper-metabolizers often need two injections. They do not necessarily need a larger dose, simply take the same weekly dose and split it into two smaller injections.

In most cases, the above injection protocol will fix the issue. However, you also want to keep an eye on your estradiol. Testosterone can cause estradiol to go up due to the conversion through the aromatase enzyme. If you're aromatizing heavily, this is more or less stealing from your testosterone and sending estradiol upwards. Make sure your doctor is checking estradiol.

Lastly, if these things do not fix the issue, you may need to look at possible adrenal fatigue. Have your cortisol levels checked and go from there. If that happens to be the problem, adjustments can be easily made.