How do I get my iPhone SE out of boot loop?

We don't know what "suggestion" you tried, but if you take the phone in to the Apple Store or an authorized Apple service shop, the technician will first try a Forced Restart, so if you have not already done this, now would be a good time.

Force restart iPhone - Apple Support

There are only 2 possible results when you perform a Forced Restart:

1) The phone returns to normal operation.....or, if the phone does not.....

2) There is likely a hardware problem with the phone that will need attention at the Apple Store (make an appointment) or take the phone to an authorized Apple Service shop.

You can find a list of authorized service shops in your area using the link just below:

Find Locations