It is hard to take thing to heart especially on a forum, like tone. I don't think he was calling you a liar. CaptianAhab is one of the newer members to the site, but I have seen him give nothing but great and consistent advice. Don't sweat it, I know you are trying to help your fish, but we really need to know exactly what happened so we can help and get you up and running.
Ok, now onto the issue.
From the numbers you are posting, it looks like you are going through a cycle.
1. Ammonia spike
2. Decrease in ammonia with an increase of nitrItes
3. Decrease in nitrAtes with an increase of nitrAtes
4. 0 reading of ammonia and nitrItes and a (possibly) high reading in nitrAtes.
So that is the basics of a cycle.
If you added more fish, there is a possibility that the increased bio-load may have caused another cycle.
Remember, the beneficial bacteria (that is in your tank) can only process so much waste (fish waste and such), if you add more waste, the beneficial bacteria can not convert the ammonia to nitrItes to nitrAtes fast enough, causing a cycle. The same thing can happen if one of your critters die, the decomposing corpse will give off ammonia and the cycle happens (or can happen) all over again.
I hope that helps you understand a little more on what is possibly going on with your tank.
PWCs or QT or rehousing the fish to another established tank are about your only options at this point.