I had your issue when I was that age—sitting at a skinny, fat 135, unable to hold onto any muscle. Any gains I made were wiped out by an illness or a short to moderate break from lifting.
Come to find out, I was one of the unlucky that had my testosterone drop heavily in my mid 20's. I delayed being on TRT for a while to have kids, but in retrospect, I should have just gone ahead with it using HCG in addition to the Test. Because having no energy to work out and was frustrated, I could never hold on to everything. I just gave up and got fat. Now, obviously, there is a lot of in-between to that, but looking back, I do regret not getting on TRT earlier.
Now, if you are not low, then don't hop on the TRT/Steroid bandwagon. It's best just to avoid it, but if you are clinically low, it can do wonders for you.
I got back on it earlier this year and started a workout program in March. In six months, I gained 21 lbs of muscle and lost 33 lbs of fat. To be fair, I started from a really bad place at 240.