That's almost surely a suction side air leak. Stop that air leak and the pump will probably produce about 15 times the volume you are getting.While the pump is running the basket is about 1/2 to 3/4 full if water.
Check that 90 degree joint where the water comes into your pump. That looks crooked to me and that joint may have failed letting air in constantly.
You have a mess. You might want to consider a pro coming in and fixing all this stuff. We'll sure help if you decide to DIY but you've got some work and learning in front of you.....sorry, but I am being candid.