Have fun: Stephen King's description

The text below is obviously told by a hick with broken English. So take it easy. I know I can ignore such English, which is not worth to learn. But understanding is necessary sometimes. Have fun if you'd like to reply.

(The parts in red are what I failed to get)

Context:

“Nothin’… nothin’… the colour… it burns… cold an’ wet, but it burns… it lived in the well… I seen it… a kind of smoke… jest like the flowers last spring… the well shone at night… Thad an’ Merwin an’ Zenas… everything alive… suckin’ the life out of everything… in that stone… it must a’ come in that stone pizened the whole place… dun’t know what it wants… that round thing them men from the college dug outen the stone… they smashed it… it was the same colour… jest the same, like the flowers an’ plants… must a’ ben more of ’em… seeds… seeds… they growed… I seen it the fust time this week… must a’ got strong on Zenas… he was a big boy, full o’ life… it beats down your mind an’ then gets ye… burns ye up… in the well water… you was right about that… evil water… Zenas never come back from the well… can’t git away… draws ye… ye know summ’at’s comin’ but tain’t no use… I seen it time an’ agin senct Zenas was took… whar’s Nabby, Ammi?… my head’s no good… dun’t know how long sense I fed her… it’ll git her ef we ain’t keerful… jest a colour… her face is gittin’ to hev that colour
sometimes towards night… an’ it burns an’ sucks… it come from some place whar things ain’t as they is here… one o’ them professors said so…”

MOre:
https://emiliosrealmofhorror.wordpress.com/