Bitcoin payment gateway Question (setting up a p2p marketplace)

I'm looking to set up a website to sell digital products (accepting bitcoin/alt ) \

like : selly/shoppy/rocketr

this is my purpose :

1. Buyer buys an item, sends bitcoin to the address handled and displayed by the website(checkout page)
   
   1. Once we receive the coins, the coins automatically get sent to your provided address minus the cutoff percentage
      

my cut off is 3% for each successful payment from a buyer => then BTC needs to release from received wallet -> 97% for sellers address and 3% for my address.

The problem is I don't know how to set up a bitcoin payment gateway for this case?

Due to the nature of the business, I can't pay any other merchants to receive payments like (bitpay/etc)

​

Please let me know the best and most efficient way to accept bitcoin using my own payment gateway or any other low-cost payment gateway for crypto.

please share your thoughts. ( I'm a newbie for bitcoin node - guides are welcome)

Thank you.

​

[Imgur](https://imgur.com/3Qsggcl)