had this happen to me on my first experience with the plains. was near a swamp and mountain too. there was this little sliver of black forest though and i was able to set up a base. tried the naked run a few times, but the place was just a warzone so everything was always aggrod and as soon as i came anywhere near they'd spot me. eventually i was able to find a decent position btwn the mt and the swamp at the edge of the plain and shoot the skeeters camping my gear. then i threw up a portal near my many death markers, grabbed my stuff and went back to base to unload. last thing i did was make a new boat, pick up my portal and sail out to the cargo boxes to collect the last of my stuff before i gtfo'd.
still i think i had to take a day off during that adventure bc i was getting too mad. just slowly work your way back to where you died and be ready to kill anything there and/or portal out quick.