How do I defeat Dragon Priest Nahkriin?

I've been flown to a temple to kill Alduin but I'm not strong enough to get past Dragon Priest Nahkriin. He's killed me over and over in 2 shots that come faster than I can deal with and so I'm fairly sure there's nothing I can do.

However the dragon that flew me to the temple has disappeared and even if I go back to the spot he dropped me off and call him he doesn't return. I can't fast-travel from this location, either.

I don't have any previous save files as I didn't think this would be an issue. Is there anything I can do?

I ran off to the left, there's an area on the side where I was able to go that he wouldn't follow me to. I just stayed in the back there and shot arrows at him. When my health would get low, I'd go off and heal up. He doesn't regen health so you can just sit there and peck away at him.

If you don't have a bow, maybe get close and then use the ethereal shout to go invincible and run away to the safe corner I was describing.

Kinda cheap but it seems like you're stuck.

If I remember correctly, you will learn the storm shout right before this guy. Nail him with thunder, and he will be a walk in the park

When you are in the building you get storm call. When I went outside there were draugrs and dragons and I was only level 10 when I did this. There are dragons landing constantly, and there is like a broken castle right in front of you. When you go outside use storm call and go hide in the broken castle and do that over and over but storm call takes forever to recharge. Storm call is good against nahkriin too. Also there are elder dragons on top of the pillars and do not shoot them and they wont attack you; They will just sit there. I have only killed 5 dragon priests so try that and it will be good.

You can drop him down the first square hole, and he'll be glitched there. Take your bow, shoot, and duck back when he fires at you.