IPhone Wi-Fi is slow and I think I know why but i have no solution?

I went on my computer and went to my router's home page. I went into connected devices and deleted my phone from it. Now it's slower than ever! I use the fastest Comcast internet available and before my phone was faster than light. Other phones connect and have amazing internet. I connect to other networks in other places and works awesomely. My phone now won't even load anything.

Your first troubleshooting step should always be to powercycle the devices in question. Though you may have deleted your phone from the connected devices page, that doesn't mean it can't reconnect, though it is possible that you blocked your phone from your router.

Before anything, turn your phone off and turn it back on. If that does not resolve the issue, unplug your router/modem wait a few seconds then plug them back in. Wait 5 minutes for your router and modem to reinitialize. If that does not work, go back into your router's utility page and find the connected devices area again. There should be an area to look at blocked devices. If you find this, see if any devices are blocked and remove them if they are. If this does not fix your issue, there may be a deeper malfunction with your router and you may want to contact the manufacturer for advanced troubleshooting.

Power cycling can fix a lot of problems, especially those relating to your home internet connection.