WEB3 send Transaction deduct fees

[ben29]

I'm using WEB3 version 4.0.3

for example i want to send 0.1 ETH.

so to send that i need Gas.

so what i try to do is:

The current amount to send minus the fees
(0.1 - 0.000003 for example)

But i always get:

insufficient funds for gas * price + value: address 0xb97170623721F86E7d9756E72668f9A209A4e8Ad have 10124457040804150 want 11032599524271312

app.post('/send', async (request, response) => {

    const gasPrice = await web3.eth.getGasPrice();
    const gasLimit = 21000;

    const from = 'FROM_ADDRESS';
    const to = 'TO_ADDRESS';
    const amount = utils.toWei('0.1', 'ether').toString() - gasPrice.toString();
    const privateKey = 'PRIVATE_KEY';

    const nonce = await web3.eth.getTransactionCount(from, 'latest');

    const txObject = {
        from: from,
        to: to,
        value: amount,
        gasPrice: gasPrice,
        gas: gasLimit,
        nonce: nonce,
    };

    web3.eth.accounts.signTransaction(txObject, privateKey)
        .then(signedTx => {
            web3.eth.sendSignedTransaction(signedTx.rawTransaction)
                .on('receipt', receipt => {
                    console.log(receipt);
                })
                .catch(err => {
                    console.log(err)
                })
            ;
        })
        .catch(err => {
            console.log(err);
            error('something went wrong', response);
        });
});

what I do wrong?