Hello utey.
Looks like you have something loose in the motor and you will have to pull the sump off to investigate . You can remove the sump without pulling out the motor by draining the oil then unbolting the front engine mount and either loosening off the side engine mounts or unbolting them as well. Jack up the front of the motor just enough to get the sump out,not to much though.
Not sure about the side mounts as I used to do it about 30 years ago on my mates FC as it regularly dropped the number 5 big end bearing due to crank flex.
Once the sump is out , have a look in the sump and you should find what the big end or crank tried to push through it.
I would advise you not to even start it again until you have looked at this as it seems that something half the size of a tennis ball is trying to escape from inside the motor through the sump
you may end up with a big hole in the side of your block.
You say that it has been running with this problem and still is so hopefully you will be able to fix the problem without any more damage occurring.
Good luck, hope this helps
Brad.