itunes icon stuck on screen

Someone please help me! I recently updated my iPhone to the new iOS 8.4 and it has completely ruined the phone now! It's constantly stuck on the iTunes red icon with the USB icon, or it simultaneously restarts and gets stuck on the apple icon. It also doesn't turn on at all when it's unplugged! I did everything the update was asking me to do, I plugged the phone into iTunes and it says to update or restore, I've tried both options more than once now and getting tired of trying. I have done the whole hold the power button and home button idea several times too, as well as trying it in DFU mode. I've also resorted to downloading and paying for Tenorshare iPhone Care Pro to see if that will do anything. I thought I was getting somewhere, as that seemed to have gave me the idea that it was fixed. But when I unplug it from the USB it doesn't turn on still. I don't really want to go into the Apple store cos they won't want to help me without taking my money first and they may not even be able to fix it! I've only had the phone for over a year, can't afford to buy another one 😟. Please help someone! I'm quite in with technology, but this has honestly given me major headaches!