What teas did you order? The different teas don't all require the same exact brewing. For example, li zi nutcracker gets bitter with 180F and 3 minutes. You have the option to either lower the temperature, or brewing time. Either use about 160F and 3 minutes, or 180F and 1m-1.5m.
If you feel courageous, try boiling water for green tea. As long as you lower the brew time a lot, and pour it carefully on the walls of the vessel instead of directly on the leaves, it won't create a bitter or stewed cup. I find that 15-45 seconds is all it takes for green tea. 15 seconds being for teas like li zi nutcracker, or sencha. 30 seconds for mid-range teas. And 45 seconds for teas like green pekoe, white monkey, and white tea.