pleasureable desire?

Really understanding the difference between desire and pleasure..
They both exist and are related, but the difference is where the two are located.
I wonder whether you can tell the difference?

Desire is a chase, and thus when you find what you sought, that desire destroys itself.
Cocaine is a desire drug, people will get the fine powder and test and rate it, look at it and smell it before ingestion. They know the quality, and they know it when it's a good hit.
A cocaine addict will chase (desire) this quite frequently, their life is run by one hit to the next. And when the drug is administered the desire is gone and pleasure is found..
Until of course, the drug diminishes and thus, desire comes back in full force, I need that next hit to get that pleasure..

This is how I can tell whether something is really going to be good or not.
The more I desire something, the harder it will be when I lose the pleasure and gain another desire. It's a reoccurring chase for something that most can't find unless they fill their craving..
Pleasure is contained in the moment, it does not seek to destroy itself.
This is why LSD is awesome, if administered in the right setting it will give you a lot of pleasure.

Now this comes down to me, and how much I desire different pleasures.
Because now I know, if I desire pleasure, it will most likely be killed at some point and il be on another chase, so this pleasure is only temporary, as long as it is filled (addiction, craving substance or act.. eg cocaine or in my example, sex).

The definitive difference between the two is the chase, because pleasure is held in the present it does not seek outside of itself, it merely is, and merely is pleasure.
This is why desire sucks, because you will not ever be fulfilled if you're chasing an object that you created..
Funnily enough, this object does not exist.