I think the blazer looks fabulous, as does the outfit, but all your analysis (and that of other fabbers) of why it's not working for you seem spot on.
I totally agree that short hair can make menswear styles read too masculine. I feel the same way. It isn't true for everyone, but often is.
If there is any doubt left in your mind (and it sounds like there is not), go back and read what you wrote "I don't want to have to work that hard" I have a similar descriptor I use for something I'm "Trying too hard to like".
And one last comment, that necklace is GORGEOUS! I want something like that. I went over to the Club Monaco site but they don't have anything like that. You have the BEST jewelry!