if it burdens you mentally and you absolutely cannot come to terms with it, then you just have to get out of there
from that perspective, selling without a loss or renting out would be the best option
otherwise try to deal with the circumstance:
- new windows and walls with better noise protection (but makes little sense in a new building)
- soundproof wall (may cost light and view)
- install sound-absorbing acoustic walls inside, they reduce the room size but might help somewhat
- other sound absorbers (there are now certain high tech solutions, talk to an expert)
- simply live with it
in the end, you of course have to consider your financial situation
and for the next plot purchase, as a precaution you should spend a night in the tent during the week (not on the weekend) so you can better assess the new building site