It's not something to take lightly, I'm sure there is a reason why you stopped cycling and if you go back to thinking of why it may give you some pause. I know myself I romanticize all my runs in my head when I'm off and then go back to my logs where I'm listing all these problems I had complaining about being on cycle.
If your diet has been in check for 6 months and you've been hitting it hard with your muscle memory to still be that far out of shape it sounds like things got really bad which would explain why your levels are tanked, at 5'11 280 you're still way out of shape. All that extra weight I'm sure is contributing to feeling fatigued, I know it definitely wears me down when I'm heavy I'm 6'1 240lbs at the moment and it doesn't feel good carrying this size day in day out, I'm out of shape and I feel it.
Another thing I will say and you can ask anyone who has been on for a very long time, that first initial boost will have you feeling great but eventually it just becomes normal and you're still going to feel the same beating yourself up in the gym every day, it's a slippery slope. Keep in my mind you're going to be jabbing yourself with a needle for the rest of your life and all the consequences that come with it, you may want to do everything possible to make sure that is the right decision. There are other things you can use to give yourself an edge that are not a lifelong commitments with lifelong consequences, maybe start with GH and synthetek products and see where that gets you. If it's the fat you are most concerned about there are helpers for that as well which I'm sure you're already aware of.
One more thing to consider, is this a "anti aging" clinic type of doc or is this your PCP telling you all of this? Be careful, just because they are called "doctor" doesn't always mean they have your best interests in mind or even know what they are taking about. At your size it's kinda concerning that he didn't tell you to drop some fat first instead of trying to sell you on TRT.