Updating mod versions can be a bit of a pain, but is usually possible so long as you're a decent Java programmer. You need to be good at Java because you will have to hunt for equivalent functionality which sometimes has been significantly changed. Also sometimes little things like renaming methods happens which can be a pain to track down.
I do give some general advice on updating mods, as well as some specific tips for updating some things in my tutorial here: http://jabelarminecraft.blogspot.com/p/minecraft-modding-updating-your-mod.html
My tutorial only has specific tips up to 1.10 (still working on learning the 1.12 stuff myself) but those will still apply to you as steps along the way. Hope it helps.