How do I replace or even find the thermal limiter for my frigidaire dryer?

This link (http://www.davesrepair.com/DIYhelp/DIYthermalfuses.htm) might help you find it. Once you've determined that is the problem, you should be able to get it at any decent appliance parts store (or online, but you'll pay for shipping).

Hope this helps,
WallyH