I have lack of motivation in all the following....even showers feel just too much of a task,
No longer finding joy in hobbies
No desire of social interaction, or making excuses to get out of social situations.
Reduced or no interest in sex
Sleep about 16 to 18 hours per day
Yes, of course yuou should see a doctor. Depression isn't necessarily your problem as the symptoms you give could be many things. I'd ask the doc to organise a complete physical first, blood tests, xrays etc. And then see about a diagnosis.
The physical tests are essential but most docs just ignore it and jump right to depression.
The sleeping that many hours a day suggests it may not be depression. And do keep in mind f you sleep that much then of course you won't want social interaction and will ensure you cannot be involved in not washing and keeping you appearance up to scrath. You could start with just doing that, shower and dress nicely each day and see how you feel.
But go see a doctor for heaven;s sake. I'g guess a therapist would be best first if no other results from the testing. Meds may be needed later but irt is a hard road and ucky dip for many of us so go there only if really needed OK. I happen to be a meds for life person but I still hate the damned things, Without them though? Nothing to be here for.