Your desire is controlled by three general factors -- most notibly your levels of free testosterone. The others are your energy levels / tiredness, and how much you are able to focus or "get into" the task at hand -- in this case, the love making. The ability to focus, however, is also a function of free testosterone levels.
You keep sounding like you want a quick fix, but if you want a REAL solution, you've got to figure out what you've been doing wrong for the past few years.
There are several things you could look at. Maybe you've been consuming too much by way of soy products, or maybe you've eaten years worth of "too high" levels of land-based meat products -- products like beef, (and to a slightly lesser extent, chicken and pork) which are high in saturated fats and cholesterols. Your blood flow / circulation could be poor.
Maybe you don't exercise enough and therefore, your testosterone production has dropped because of lack of need to build new muscle.
Maybe you've been very overweight, and you're now on a diet. Releasing the fat in your body will release stored estrogen into your blood.
Perhaps, in contrast, you're a strict vegan and are not getting sufficient quantities of body-ready protein or are missing certain proteins in your diet. Minimum daily protein intake (in grams) should be body weight (in pounds) multiplied by 0.36. This is for a completely sedentary person. An active person exercising regularly and strenuously should be consuming more like 0.62 to 0.75 times body weight in grams of protein per day. The slight increase in protein causes the thyroid to adjust in such a way as to bring more free testosterone into the flow.
Maybe your zinc levels are too low or too high. Most men should have somewhere around 15mg to 45mg per day TOTAL. Too much can be toxic and also cause impotence. Too little can cause impotence.
There are other possibilities too. Maybe you've been concerned about prostate health and have been taking regular doses of Saw Palmetto and/or Nettle Root for some period of time. While these are good supplements for specific purposes, they can also cause temporary impotence.
Perhaps you work at a very stressful job where you've been chronically stressed for months or years. This affects cortisol and DHEA levels to the detriment of free testosterone levels (and testosterone levels in general). Some herbs block cortisol production. Also, herbs such as ginseng will help restore balanced endocrine function. Veggies like raw cauliflower will help a functioning liver eliminate excess estrogens.
Maybe you just need a really good systemic cleansing, or maybe there's some presently unknown medical condition you're experiencing such as diabetes.
Like I said, you need to figure out what is going wrong in your life and correct that to bring back the balance before you will be able to reduce or eliminate your problem(s) in the bedroom.