LINODE production {"status":"500","code":"ECONNREFUSED"

Hi everybody,
This morning I just published my web app in production since i did minor modifications to https://v2.giloo.me/ that is hosted on Linode

Since i Got this result

{“status”:“500”,“code”:“ECONNREFUSED”,“message”:“connect ECONNREFUSED 172.19.0.3:5432”,“stack”:“Error: connect ECONNREFUSED 172.19.0.3:5432\n at TCPConnectWrap.afterConnect [as oncomplete] (node:net:1494:16)”}

While refreshing the page got this second one

{“status”:“500”,“code”:“ENOTFOUND”,“message”:“getaddrinfo ENOTFOUND db”,“stack”:“Error: getaddrinfo ENOTFOUND db\n at GetAddrInfoReqWrap.onlookup [as oncomplete] (node:dns:107:26)”}

It looks like my DB connexion does not work anymore… I did not modify it.
Any ideas? Service is down… and i really need to find a solution urgently.

(App works perfectly on localhost…)

Many many thanks