The most helpful piece of advice I can give you is to strip away your ego.
There was a man I once knew who made a name for himself online with his stories. Back in the 2000 - 20005 era, he was one of the more influential creators, and he actually built himself a fairly large fanbase. But, as the years went by, more and more new members joined the site he posted his work on. Most of them were terrible, but a few of them were good, better than him. Instead of actively trying to improve himself he just became more and more self delusional.
It wasn't too noticeable at first. He just made the logical leap that since he'd already risen to the top of the pile, he would remain at the top of the pile forever. Except, more and more the others started overtaking him, and he kept getting more and more detached from reality. That's when his writing really began to suffer. He slowly stopped looking at his own work critically, he stopped editing, he stopped asking for help, because why should he? He was still the best, wasn't he? One by one, his fanbase left him, and his friends started having to make excuses for him.
He became paranoid and bitter. Whenever someone reviewed anything he'd made negatively, he always accused them of having some sort of personal bias against him. It was around this point where the quality of his writing really took a nosedive. He made mistakes. Stupid, easily fixable mistakes. The more people pointed them out, the more he decided that there must be some conspiracy against him. He's a pariah now, and he hasn't written anything in years.
One of the first things I did when I started writing was to make sure I never became like him. Some Beta Readers will give you good advice. Other Beta Readers will give you bad advice. As a Writer, you will need to decide what you will and will not listen to, but, never dismiss criticism out of hand because it offends you.