Drink half a bottle of tequila beforehand. lol
Ok ok, I know YOUR advice was more along the lines of "have one drink" but regardless of the amount, alcohol does tend to desensitize you and can make it easier to last a bit longer, or in the case of many of us old fuckers, make it harder for us to finish. which I guess it the same effect just a different POV. lol
Here are two other pieces of advice for the OP which may or may not be helpful depending on his circumstances and his ability to actually try my advice. The first one is easy, depending on how long his recovery time is he could try making longer appointments ONLY with providers that allow MSOG this way he can get one quick pop and then have (hopefully) a slower paced and more leisurely second go at it.
My other advice may or may not be practical but it sure worked for me when I was younger and wanted to train myself to last longer and that is have sex A LOT, The more sex you have, the more you are able to control yourself and the less nervous you are going to be about it. Try going on a "fuck fest" where you have sex several times, (as many as you can, hopefully at least 4-5 times a day or more if you are young) do this for a few days and you should be able to last much longer when you are done. Yes, this might cost a bit, if you can't afford to hire that many providers, you might try finding a civvie friend who loves to fuck, maybe even try letting a "cougar" pick you up and having her way with you, OR you might consider taking a trip to somewhere that you can do this affordably where there are hookers available 24/7 at an affordable rate like maybe the Dominican Republic. It will still cost you a few bucks, but it shouldn't cost you much more than $2-3 grand on a budget for a long weekend of fucking, including air fare, food, drink hotel and hookers of course. Once you fuck 15-20 different women over three or four days you should be good to go. Sex will be completely demystified. lol