Screen starting to get deformed?

Hello,

After three years and a half of using my iPhone 5, I started to get issues.

I am the type of person who takes pretty good care of their things, I dropped perhaps twice my iPhone during its life, and never sat on it or mistreated it.

However, I am starting to have certain issues, and I am wondering if it's perhaps due to the heat?

My "home" button is not sensitive as it used to be ever since last June, especially when it's a hot weather or when the iPhone starts to get a little hot after using it for a while. So I have to sometimes press really hard the home button for it to work.

But the main issue is: the screen is starting to get off or get deformed??

THe left side of the screen is starting to get detached as you may see on the pictures. I started to realize that when I saw a light while using my phone (as of today) and never saw it before and decided to take off the case to see. To my astonishment I realized a sort of deformation of the screen in that area.

The tactility of the phone has no issues but I am getting a little bit boring.... Is it the slow death of my phone?

Will the phone perhaps go back to its usual shape when the summer ends (so when it's not longer as hot)?

And what solutions can be given for this?