Cryptography substitution frequency analysis
I'm by no means an expert but it seems to me that your sample is far too short to be amenable to frequency analysis or, indeed, to cryptanalysis of any kind. Assuming a substitution cypher, you have only the information that eleven letters are used, and characters 1, 4 and 14; 3 and 10; and 8 and 11 are the same. There are fifteen unused characters so there's a huge amount of freedom. You only have a little more information than a one-time pad would give you.

In a long sample of text, it is likely but is not guaranteed that the most frequent character is 'e'; in a fifteen character sample, it's perfectly possible that there are no e's at all. ("Look at my odd words" is a sixteen-letter example.) Frequency analysis helps you figure out the substitutions but it doesn't guarantee to give you the answer with no more work.

Assuming the spaces are significant, your message could be "My emus love no imp". Or it could be something completely different.