* If we had followed the procedure, we wouldn't be in such trouble.
* If we had followed the process, we wouldn't be in such trouble. (Grammatically correct but sounds weird because you follow a procedure, not a process.)
A procedure is a series of small tasks you perform to complete something. In other words, the exact list of instructions that you have to perform.
A process is an outline of how to complete something.
* Are these two sentences correct? --or-- Are these two sentences written correctly? --or-- Are these two sentences written correct? (Informal American English which drops -ly often.)