iphone 6 wont start after dying

Hey everyone,

My iphone 6 has been causing me a lot of grief recently. it started when my charger port wouldnt charge my phone correctly unless i was to push the charging cord with a lot of upward force while pushing it to the right. it would eventually start charging without me holding it in place, but that would take about 5-10 minutes of me fiddling around with it.

but just last night i made the mistake of letting the phone run out of battery. Now i do the usual to charge it (read above) and then it shows the apple logo for maybe 3-4 seconds, then goes black but remains lit up and then proceeds to turn itself off again (without showing the little wheel thing that it normally shows). this just repeats itself over, and over again.

so I'm not sure if this is a hardware or software issue. if someone could tell me which it is (apparently updating to ios 9.01 or whatever the latest one is, is meant to "fix activation errors on some carriers". or if my charging port is busted and that i should look into buying a new one.

I'm not big on computer language with all the small parts, so a simple explanation would be great!

thanks for helping!!