A few ways you can approach this.
Depends on what you mean by "feeling low T" and "losing your edge".
There are conceivably plenty of good options that may not necessarily boost your T (which just going on feeling may mean you don't even need a boost) that will have you feeling better both in and out of the gym. It is important to also realize "losing your edge" in the gym could mean so many different things and that the longer we train the slower results will be no matter what, it just is how it is.
Something like SNS Anabolic XT likely will boost T anyways, but I find it give all the "feels" of boosted test like improved libido, sexual performance, mood, and "vitality", while also boosting things often associated with improved test in the gym like pumps, endurance, strength, and progress.
There are many other things that could potentially work in this way as well, without necessarily directly boosting test (that is not to say they won't also do that).
Or you could look at things that directly impact test levels that many have found lots of good results from like CEL M-test or SNS Optimize-T. If actual testosterone boost is your goal those would be good options.