Cannot progress in story mode, please help.

[bigdonut22]

(PC Version) I am at stuck at the part where I need to get the submersible as Trevor for the merry weather heist (I chose freighter option). I have everything checked off on the 'to do' list except getting the submersible. Strangely, at first after starting the heist setup mission, the orange H - heist icon appeared where to steal it. I at first did not go and do it, instead I did a few strangers and freaks side missions. After that I noticed the H no longer appeared on the map, I even tried going to where the sub is located and tried stealing it that way but it did not even appear on the crane. I completed all the missions I needed to complete like the long stretch, hood safari, by the book, etc. I've literally run out of all missions. I checked in the brief option and says no jobs available. It seems it may be a bug of some sort and I really hope I don't have to start over.

Edited April 29, 2015 by bigdonut22