how do i erase my iphone

OK.....I've given you two links to help you. After following the directions in the links, what didn't work? Just plugging into either a PC or Laptop isn't enough. You have to have iTunes, which is updated, installed and open. Also, many PCs/Laptops, especially older ones may not output enough power to charge an iPhone. But you're not trying to charge your iPhone. You need to erase it using iTunes on your computer. And I provided the directions on what you need to do for that as well.

See what you need to do by following the directions in this link EXACTLY --> If you forgot your iPhone passcode - Apple Support

You MUST use a computer. What does "it won't connect to any of my computers" mean exactly. What won't connect? Do you not have a cable that will connect to the computer or does the computer not recognize your iPhone?

If your computer doesn't recognize your iPhone, see this link --> If your computer doesn't recognize your iPhone or iPad - Apple Support

If you have any type of mac, plug it into itunes and erase it. If you have windows, download itunes from this: iTunes - Apple and do the same process after setting itunes up as done on the mac.

What is happening when you;re trying to connect it to a computer? You must get it connected in order to complete this procedure.

"cant use a computer because it wont connect to any of my computers"

Can you clarify on that for us? The iPhone connects to a Mac or PC for the setup. You don't connect a computer to a computer.

You're welcome. I was pretty sure you didn't have iTunes on your computer and without that, you'd have gotten nowhere.

Can you still reach the Apple Store?