Find a cafe or coworking space. You're in Nantes, right? Check out the Nantes Cité des Congrès and Nantes Route de Paris, they both have dedicated coworking spaces. Personally I would find something right on La Loire or L'Erdre so I had a nice view of the water; really any view of nature I think will help, even if nobody's around. After work, get out and find something to do with other people.