How to get damaged hair back to normal!?

Well, my natural hair was very thick and curly (ringlets) i had such long hair and it was soo curly until i started straightening it and dying it, it was alright after the first couple of dyes but its never been able to grow fast due to how curly it is!:( - i had it cut about a year ago and its not grown since, i straighten it everyday and i dont use heat protection!(n) .. my hair wasnt that bad until recently i bleached it because it was black and i desperatelly needed to get it lighter again, im annoyed with myself because ive ruined my hair, it was soo long and un-damaged and its not grown in ages, im thinking of wearing it up in a bun naturally and im gonna start using hair treatments for extremelly damaged hair (if anyone reccomends any hair products PLEASE let me know what they are) also, if i want it to grow, do you suggest i have it trimmed to get rid of the split ends and keep wearing it natural without using heat etc. will it grow? and will it all mend if i stop with the heat and hairdye? XX