your tank readings say you have ammonia..and you use test strips...there shouldnt ever be ammonia because its a killer ...test strips arent reliable so before you freak about the ammonia, make sure you have some with a more reliable
test kit...alot of us use an
API liquid master kit which has all you need for great fish keeping....if you cant get that, at least get the api liquid ammonia kit....if you do have ammonia, getting some prime water condtioner and doing daily water changes with it will detox the ammonia for 24 hours until your next
water change.....after 2 months of running, you should be close to a cycle completion...it will be done when you have 0 ammonia and nitrites and under 20 nitrates...I wouldnt add anymore fish until you figure if the cycle is complete....swordtails are lil piggies when it comes to food so him not eating, is probably the effects of the ammonia ...goodluck!