My iPhone won’t turn on since upgrading my storage

Hi, since upgrading my storage yesterday to 2TB my iPhone won’t turn on. After I upgraded it everything was fine, and then it started to close my apps while I was using them. So I turned the phone off to restart it. But now it won’t turn back on, it just showing the apple sign and won’t do anything else. Occasionally the apple sign goes off and the screen is black but then it comes back on again. I’ve logged into my iCloud on my iPad and everything is backed up. Can you help me please. I’m also on vacation in Barbados so don’t have any apple store to go to or I would.