Q: iPhone lagged and irresponsive

I have iPhone 6 64 gb, got it slightly more than a year ago.

My iPhone was working perfectly before I updated to iOS 9.3.3, then I started to see some lags, but it was okay it was bearable and at least the touch screen was working, these lags took at least 30 mins before getting back to normal.

After releasing IOS 9.3.4 I downloaded it immediately thinking it's my savior, but the bad news it got worse, my phone actually kept lagging, crashing and unresponsive for an hour, then it went away by itself, since then my phone became unresponsive for an hour everyday since that day I got the new IOS.

The thing is that I'm sure it's a technical problem, and it's not my fault, I actually care about my phone like it's a baby. The screen doesn't have a single scratch, never touched water or exposed it to humidity or radiation..

And I can't afford right now paying for a new iPhone or fixing it, since the warantee is expired.

I contacted Apple support on Twitter and eventually they couldn't help me!

I can't believe that I'm dealing with the biggest multinational technology company and they can't even help me with my phone!

it's the worst phone experience I had after switching from being android user to IOS user.

Please help!