This song is up there on my favorites list from "I and Love and You," so I just tried to figure out the basic progression for guitar. It may not be 100%, but it has worked for me!

Incomplete and Insecure

(C)I haven’t finished a (F) thing since I started my (C) life
I don’t feel much like (G) starting now.
(C) Walking out lonely has (F) worked like a charm
I’m the (C) only one I have to (G) let down.

(Am) But watching (F) you makes me (C) think that that is (F) wrong

(C) I can go on with my (F) insecure nature
I can (C) keep living off sympathy. (G)
I can (C) tell all the people that (F) all of my success
Is a (C) direct reflection on (G) me.

(Am) But watching (F) you makes me (C) think that that is (F) wrong

(C) What is important? What’s (F) really important?
Am (C) I not to know by my (G) name?
Will I (C) ever know silence (F) without mental violence?
Will the (C) ringing at night go (G) away?

(Am) It’s up to (F) you.
My (C) father told (G) me.

(C)I haven’t finished a (F) thing since I started my (C) life
I don’t feel much like (G) starting now. x4

(C)I haven’t finished a (F) thing since I started my (C) life. (G) x2