CrossRoads ... or not

I'm just at a very difficult part in my professional career as this year winds to a close.  I have been with my current employer for the last 4+ years and have probably done more here than at any place I have worked before.  Not combined for everywhere, but I have been involved in two reactor installs and have been involved in all of the instrumentation and commissioning of every new piece of equipment that has been brought on-line in that period.  So I feel like I have done a lot and I definitely have the knowledge of all these new pieces.  So onto the cross road part.  Well recently my boss got promoted (congrats), but I did not.  That's okay as I don't really have a back up and no one is in a position to do my job if I moved up so I would essentially be stuck doing two full jobs which would be impossible.  But (and there is always a but right?) when the move happened I wasn't involved in any of the talks.  Well that's fine as I'm just a lowly process engineer, but I was told that I would be reporting to the production manager who was going to take over some of the site manager responsibilities.  I said that wouldn't be a problem as that was my gut reaction to be a good little soldier and not a problem maker.  After about a week, December 8th to be exact, it starts to dawn on me that 1) I wasn't consulted in any of the decisions and am the 3rd most tenured person at the plant now, 2) my responsibilities seemed to increase after my boss left with no increase in compensation even though the new manager got a promotion and raise.  Now I'm not one to begrudge someone else but the person that got the promotion was in a similar position on the org chart to me, but now I'm below them.  So this is indirectly a demotion for me.  Now I'm second in tenure at the plant, but aren't being consulted about any decisions related to the plant.   So in the first month of this experiment I've watched us run our most critical chemical level down to a point where we didn't have enough to neutralize our tank, and the level in the tank has dropped off the thermocouple, so we have run the pump in manual for the last 2 weeks because the automated heating and cooling cycles won't work.  We ruined a pump and in haste to neutralize a tank used a chemical that we haven't used before and it corroded the inside of the tank.  To boot the only reason that we didn't have more issue with the chemical tank was because I just happened to realize the cooling system was trying to run, but wasn't working and the tank was heating up by the constant recirculation.  I'm just at a difficult point because I have seen a lot of other plants close and fail, and I don't think we are there, but there has definitely been a change in the last month that isn't a positive.  I don't really want to leave because of all the time and work I have put in, but I question where my ceiling is now.  Clearly I'm not getting the credit, or should I say some other people are extremely good at taking credit, and now if I say something to management it will seem like sour grapes.  Also the people that I work with are slowly starting to grade on my patience and there are about 4 people that I try and avoid at all costs, which is not good for a work environment.  At any rate this is just kind of an exercise to help me think through things and really give myself some perspective.  Every time I have left a job in the past has been out of necessity to stay employed and this would really be the first I have left because of work issues.  I honestly don't see a way out, but it is going to take a while.  All I can do is put my faith in God that he has guided me through things before and done it for a reason.  If my purpose has been served here and it is time to move on then great, but if I'm supposed to persevere to learn something then that is going to be rough.  I know how hard it is to start over and my past is about 4-5 years and hit the reset.  I have about 20 years left and there is no way I'm going to be miserable working for the next 20 years.  Peach said she wants me to be happy, but that is a hard thing sometimes.  What really makes you happy?  Knowledge of what you are doing?  Comfort where you are working?  Not having to start over again?  Feeling that what you are doing matters and getting recognized for it?  Well I know what being miserable is, happiness may just have to wait.  Hears hoping 2018 goes better.  Good luck everyone.