Don't worry about that, I did the exact same thing, cycling with a damsel, because my LFS told me that was what you do. I did not find this message board until about two weeks after I started to cycle. I have only had my tank for about four months now, I just got my MH lighting the other day, but have not hooked it up yet.
I also want to get some anemones and corals, and deffinitely some clams (how this thread started).
The hardest part about this hobby is the patience, at least for me because I am a very impatient person, that might come with being a guy, immediate gratification and all....
But that would be my main advice to you, just slow down and be patient,
As hard as it may be for me, I will actually wait at least another 2 months until I add any anemones or corals, and it will be hard. My water perameters have been constant for past 8 weeks. AM=0 trIte=0 trAte=20 salinity=1.025, temp=79.