My first tab, lmk feedback in the comments. Transcribed by ear. The entire song is the verse on repeat, 
besides the (pre)Chorus. 

Verse *repeat to preChorus* 

G|----6---------8-11-----8-6----------6-----654----------------------8-6----------6----| 
D|---6-6--9--6-9-------8----8-6------6-6--------6-4--9--9-6-------8-----8-6------6-6---| 
A|-4-----------------9--9-------4-4h6-----4--------6--------9---9--9--------4-4h6------| 
E|------------------------------------------------------------9------------------------| 

G|----6---------8-11-----8-6----------6-----654---------------8-11------8-6-----------6--| 
D|---6-6--9--6-9-------8----8-6------6-6--------6-4--9--9---9--------8------8-6------6-6-| 
A|-4-----------------9--9-------4-4h6-----4--------6------9--------9--9---------4-4h6----| 
E|---------------------------------------------------------------------------------------| 

preChorus 

G|-----------------| 
D|-----------------| 
A|-4-4-4-4-4-4-4---| 
E|---------------6-| 


"every step I..." 

G|----------------------------------------------------------------------------| 
D|-------------------------------------------------------3--------------------| 
A|---------4-6-------------------------------2-4-4-4-4-4---4------------------| 
E|-4-444-6----4-4-4-4-4-4-4s2-2-2-2-2-2-2-2-2-----------------4-4-4-4-4-4-4-4-| 

G|------------------------------------------------------------------------------------------| 
D|------------------6-----------------------------------------------------------------------| 
A|-4--4-4-4-4-4-4-6----6-4---6-------------------4--4-4-4-4-4-----4-4-4-0-2----4(INTO-VERSE)| 
E|------------------------6----4-4-4-4-4-4-4-2-2--------------2-2----------2----------------| 

G|----6---------8-11-----8-6----------6-----654----------------------8-6----------6----| 
D|---6-6--9--6-9-------8----8-6------6-6--------6-4--9--9-6-------8-----8-6------6-6---| 
A|-4-----------------9--9-------4-4h6-----4--------6--------9---9--9--------4-4h6------| 
E|------------------------------------------------------------9------------------------| 

G|----6---------8-11-----8-6----------6-----654---------------8-11------8-6-----------6--| 
D|---6-6--9--6-9-------8----8-6------6-6--------6-4--9--9---9--------8------8-6------6-6-| 
A|-4-----------------9--9-------4-4h6-----4--------6------9--------9--9---------4-4h6----| 
E|---------------------------------------------------------------------------------------| 

Verse unil end 

"..like you promised I'd be" 

G|-----6--------| 
D|----6-6-------| 
E|-4h6----0-2---| 
E|-----------2--|