Don't quit! Learning to mix is like learning an instrument, it takes years to master and there's always room for improvement.
I won't comment on the mix itself since the biggest issue here is your monitoring setup. Mixing on a cheap pair of earphones is like painting in a dark room. If you can't accurately hear what you're mixing then it's just that much more difficult to make good decisions in the moment.
If you can't splurge on some hi end studio speakers, get yourself a pair of $100 bookshelf speakers off of Amazon or a similar retailer and start from there.