Question Regarding Swapping and Gas Fees

Hi guys.. I am new to this whole cryptocurrency.. I have Eth that i converted to BNB.. but for some reason it turned into a token into my BSC wallet in metamask.. so now I have 0 BNB and 0.15eth Tokens in my BSC wallet... Here comes the question.. I have a $10 worth In Eth in my metamask.. and i have 0 BNB and 0.15 Eth Token in my BSC wallet in Metamask.. and I want to swap the tokens in BSC wallet from Eth to BNB... Is there anyway that I can use my mainnet Eth as a gas for my swapping of BSC Eth token to BNB?.. I have no BNB to gas swapping.. Any answers are appreciated.. thank you :)