How do I implement cryptocurrency payment processing in my e-commerce application?

I totally get why you're feeling overwhelmed - there are a lot of options out there when it comes to cryptocurrency payment processing. I've been in your shoes before, and I can tell you that it's definitely doable, even with the tech stack you're using. From what I've seen, libraries like Coinbase and BitPay are great options because they support multiple types of cryptocurrencies, so you wouldn't need to integrate with each one separately.

I've used Coinbase in a previous project, and it was pretty straightforward to set up. They have a JavaScript library that you can use to integrate their payment gateway into your application. You can use their API to create a payment button, and then store the transaction data in your MySQL database. One thing to keep in mind is that you'll need to make sure your database is set up to store the relevant transaction information, such as the cryptocurrency type, amount, and transaction ID.

In terms of security, you'll want to make sure you're handling cryptocurrency transactions in a way that's secure and compliant with relevant regulations. This means using HTTPS to encrypt data in transit, and storing sensitive information like API keys securely. You should also make sure you're validating user input and sanitizing any data that you're storing in your database. I'd recommend checking out the documentation for the library you choose to use, as they usually have some guidelines for security best practices.

Overall, I think you're on the right track by looking into libraries like Coinbase and BitPay. If you have any more specific questions or need further guidance, feel free to ask - I'm happy to help. Good luck with your project, and I hope it all goes smoothly - integrating cryptocurrency payments can be a bit of a learning curve, but it's definitely worth it in the end.