Man of Honour
No. Doing core work is something you should be doing but it's part of the picture - not the whole.
I think the thing we're confused about is these "level 1"/etc " core exercises. If you can describe what they actually are I think you'll get better feedback.
In the end though, as mrthingyx says, you should probably go and see a decent sports physio. They will talk you through specific strengthening exercises and mobility movements that will help with your problems - and give you a good base to continue working on in the future so you don't run into issues like this again.
I think the thing we're confused about is these "level 1"/etc " core exercises. If you can describe what they actually are I think you'll get better feedback.
In the end though, as mrthingyx says, you should probably go and see a decent sports physio. They will talk you through specific strengthening exercises and mobility movements that will help with your problems - and give you a good base to continue working on in the future so you don't run into issues like this again.