Hitching up a Travel trailer (TT) is not that hard, if you have a rear view camera in the truck. And the same system can have a rear-view camera on the trailer, helping you back into sites, since you will be alone.
A fifth wheel hitch can stay in the bed of the truck, if that leaves enough room for your boat and stuff when fishing. A TT hitch would probably have to be removed as they stick out so much and may even interfere with the tailgate. And they are heavy.
Other problems are leveling the trailer. With a heart condition, I guess you want to do as little heavy work as possible. You can use an electric drill to raise and lower the scissors jacks at each corner of the trailer. And be sure to get an electric tongue jack if you get a TT. Not sure how you level a fifth wheel, but I'm sure some have electric jacks. But maybe not for $15,000.
Have you considered a Camper in the truck's bed? Maybe too small for an extended stay, but you can definitely get into places you couldn't with a trailer. They can have electric jacks to level and lift them off the truck. I've seen a lot of fishermen with them park right next to the river. They do require a hefty truck though.
Good luck in your search.
2014 ORV Timber Ridge 240RKS,8500#,1250# tongue,44K miles
690W Rooftop + 340W Portable Solar,4 GC2s,215Ah@24V
2016 Ram 2500 4x4 RgCab CTD,2507# payload,10.8 mpgUS tow