Now here's the point: I am running a long, epic campaign for 2 years now. Players have gone and changed throughout time, though about half have stayed since the beginning.

But since they acquired a higher level, as well as knowledge of game mechanics (5e) they constantly antagonize me, the DM, in my rulings, trying to rule bend, and abuse every aspect of game mechanic to "put me in my place", and beat the game.

I constantly find myself in a position, where I have to tell them you can't do that. For example one player wants to abuse the Bag of Holding, using it as a vehicle. Things like "all players get inside, and a dominated eagle carries us". When I told them, that the bag has a limited space, he was outraged, and visibly pissed.

When they try to beat the bad guys in a race against time through the Teleport through Plants spell of the druid, and I make the bad guys then simply use the teleport spell (they have many mages amongst them, so its nothing irrational) they get angry at me again. It has gotten to the point where I am not willing to play D&D because they are trying to wrestle all control from me as a DM, jumping and killing encounters I have prepared with a lot of care and excitement (i put a lot of passion in my story, trying to keep it full with 3dimensional characters, reoccuring themes, plot twists and dynamic relations. I even oil paint the most awesome moments that occur throughout the campaign).

I told them, that the game cant be played if the DM can't have enough control to know what to prep, but then they argue that it can. I tell them, that if the bad guys are a smart organization, of course i will let them outsmart the players, and I tell them that if they abuse the rules to do extreme things, why can't the Zentharim do that too?

It's like they don't want to have me as a Dungeon Master and play my campaign, but they want me as a Dungeon Processor who runs their fantasies of unlimited power. And when I stop them, even with the best arguments, then I am the bad guy who is ruining their fun.

The problem though is, that, how sad it might be, at this point of my life i've got nothing but D&D for fun. I work nightshift job, and work on my degree at daytime. I am constantly broke, and D&D, writing stories, making adventures and running the campaign is all I have, so I am quite anxious about breaking up the campaign, as any normal DM would have done by now. Because then I will be left with nothing, and all the heart I put in to this campaign for the last 2 years, will be dead in the water.

Is there anything I can do, any suggested course of action to get my group back on track?