I fixed it, my understanding is that mdadm.conf runs first and starts the array, then fstab runs and mounts the array.
I uninstalled mdadm using apt-get, deleted mdadm.conf, rebooted and reinstalled mdadm using apt-get, then ran "sudo mdadm --assemble --scan", this created a new mdadm.conf with the correct settings. One thing I noticed is that it put "ARRAY /dev/tsunami" (tsunami is my array name) in the mdadm.conf, I changed this to "ARRAY /dev/md0", then I added my partition (located on the RAID array) to fstab, it looks like this "/dev/md0p1 /media/tsunami xfs defaults 1 2".
Then after all this, it works!! :)