clightning uses all my resources, ... till I have to shutdown!
This is most likely the gossipd bug that was causing a request from a peer to be processed very slowly. It was fixed in PR 2268. You don't have that fix in your installation yet, which can be seen by the 5 daemons that are not being reaped correctly (the &lt;defunct&gt; processes in the list). This was also fixed in PR 2224.

Both fixes are not yet part of a release, but we will release them soon.