Should I get my testosterone levels checked?

So, it's been 4 months since I started NoFap. During the start, I felt very energetic and horny, and super confident. I was hitting the gym and seeing gains. Now, I feel... tired and lethargic. I don't have much of a sex drive. Libido is not that high. No morning wood. I still go to the gym, but it's getting harder to gain muscle and lose fat. I've started going to the gym more because of that. Could this be because of low testosterone levels?

Now, I've heard that testosterone levels decrease after 3 months of abstinence. Not sure if this is true or not. I'm not in a relationship, and probably won't be for another year (for reasons), so I've been doing hard mode all this time.

I've also heard that I can supplement with stuff like Zinc and Magnesium to help increase my testosterone/energy levels. Not sure about this as well. I guess I should probably check my testosterone levels before I start taking anything.

Do you guys have any advice? Is it detrimental to go on long hard mode streaks? I'm sure many here will not see NoFap as the primary cause, but what if it is?