I'm back with more electrical problems caused by my trailer.

I hooked up my truck last night to my 5th wheel including plugging in the 7 way in preparation for a trip today.
I start it to check the lights, lights won't work on the trailer. I find that the 40 amp trailer fuse is blown, so I replace it with a 50 amp cuz I didn't have any other 40s, and the lights come on and everything seems normal.
I turn off the truck and go inside to grab some things, about 10 minutes. I go to start the truck again and it won't start, battery seems low but it's turning over. Hook it up to jump it from another car and battery back at full but still won't turn on.
Since I'm not that mechanically savvy I find another 40 amp fuse thinking I screwed something up and plug it in and no change. One of my attempts to start it I smell a weird smell coming from it after. The only way I can think to describe it is something like paint, a smell I've definitely never smelt from a car before.

At this point I'm not as worried about why it happened as just getting my truck to start. The trailer is for sale and can be someone else's problem, I just need to start my truck and get it disconnected now.

Thank you guys in advance! I really appreciate it.

update:
few hours have gone by and it started but bogs down at first and acts weird and smells gassy. I tried revving it up and it seems to have maybe a loss of power?
I find it hard to believe it's unrelated but I guess it could be...

 

I hesitate to say you blew a fusible link as I don't know what it smelled like but a 50 instead of a 40 amp fuse when one blew might do it. Was it a sort of electrical smell?

 

I still have power to the radio and other things, I'm not sure if that changes the possibility of that or not. The longer I hold the key in the start position the more I get the smell. It's not an electrical smell in my opinion it really smells more like a freshly opened can of paint, maybe a little more sour.

 

update:
few hours have gone by and it started but bogs down at first and acts weird and smells gassy. I tried revving it up and it seems to have maybe a loss of power?

 

Is the trailer unhooked?

 

I just unhooked the trailer and now it's doing something else. It's dying immediately if I don't give it gas and the second I stop giving it gas it dies.

 

Is the battery charging?

Check engine light on?

 

The battery seems to be fine for now and the check engine light isn’t on

 

Is the alternator charging the battery?

 

Can I test this by hooking it up to a charger?