I'm not defining pleasure to mean "getting what one desires," hence it is non synonomous with the definition you are using for "utility." Pleasure is a particular sensation.

For instance. If you get something you desire, you may feel pleasure, or you may not. Or maybe you'll feel pleasure for a little while, but not as long as you expected to.

Going in the reverse direction, if you feel pleasure, you may have gotten something you desired, but you may not have---e.g. a massage may feel good even if you didn't expect it to beforehand.

When I talk about "pleasure" I do mean something that you experience in the moment---just like "hot" and "cold." You feel it at a particular time, or not. But that does not exclude a long-term experience of pleasure, such as a general state of emotional happiness. In fact, the latter is what I am more interested in.

Some people associate the word "pleasure" with a necessarily temporary and immediate experience, but that is merely a connotation, it is not the definition of the word.