how do I support my SO?

Charley Knows • 24 and living without a thyroid 💪🏼
Okay back story, we were flat ass broke for a long time. He's a builder so jobs come and go very quickly therefore money was insanely tight. I worked part time but he was so worried about it affecting my uni studying I quit. We stayed in his caravan for a while and now he has an amazing job at a caravan site doing maintanence, building, all sorts! They provided us with a Static Caravan which is amazing and we have no bills. He gets paid £350 a week which is plenty since we aren't paying for anything except our 2 cars and his phone bill. 
The management is as follows, A owns the whole site but only pumps money into it, other than that doesn't have much a say on the dad to day running, B is technically a part owner and deals with the running of the whole site, C only does my partners maintanence work when my SO is on holiday. Therefore C is the same 'status' as my SO. C thinks he runs the place, does no work when my SO is away leaving a massive list of manual work for my SO to do when he gets back. 
My SO is beyond losing it, he is stewing and stewing. C is on the same wage as him but in the last 6 days (SO has been off) he has done 3 hours work. Leaving my SO with so much to do. My SO is annoyed that they both get the same wage when C does nothing. My so has to get up early to complete all the shit work and leave late. It's a campsite so the safety and welfare of the customers is paramount! 
Anyways my SO is so angry and when he gets like this he'll just leave. Never look back. He's done it before in jobs and I can see his frustration. I'm sat here thinking, we have it made right now. He enjoys is work when C isn't being a dickwad and we have made a lovely home. I can't/ don't know what to say or do to support him because all I'm thinking about is that we can't go back to living in the small caravan with no money and no job. I'm honestly not trying to be horrible to him he's amazing in supporting me and us but it was horrible times when we were broke. 
Does anyone know or have any suggestions as to what I can do for him? I'm so lost in what to say because I kinda feel like it isn't my place as I'm not earning money right now. I'm 2 months away from getting my degree so hopefully after that and once I'm working if he wanted to leave we could. I just don't know what to do ladies! 
Thank you, sorry this is so long!