Huge sympathies @LuisaM - students like this cause us university tutors a lot of worry & concern. In the old days, with consistent absences, we'd send a member of Security staff to do what was called a 'bed check' just to see where the student was. We can't do that nowadays ...
You're right, the ball is in his court. He needs to engage with his course tutor, or the student welfare people.
You can do some things to help your anxiety about him: university regulations are publicly available on their websites, so you can go in & check what the regs for his degree are. Most (but not all) degree courses don't count the 1st year marks & grades into the level of the final degree class. But - students still have to pass their first year.
An undergrad degree in England is 360 credit points: 120 each year. But most university degree courses (not all) allow a student to "progress" with a maximum number of credit points failed, or incomplete. At my place the max. is 30 credit points. This means they can progress from 1st to 2nd year with only 90 credit points. (At my place that would be failing or non-completion of 1 module). But he won't be able to fail that many credit points again.
SO - maybe you can reassure him that:
- it is NOT a disaster - 19 year olds tend to catastrophise, in my experience.
- His tutors will have heard it all before. There is no shame. We are human, we know people have human failings
- COVID-19 has meant that in MOST universities there are extensions & mitigations galore, so if he's found the whole (government required & legislated) online thing demotivating, it's very likely that he can get extensions, or have the summer to complete work.
Maybe you can reassure him about all this, and have a chat with his tutor about best & worse case scenarios. His course tutor may be able to explain the specific university regs to you, so you can tell your DS.
But he needs to talk to someone.
We really do worry about the kids who go off the rails, but the impetus needs to come from them.