One thing did strike me as odd.
You say you have 7489 Individuals and presumably they were all born.
Yet your Birth source has only 152 Citations and not 7489?
Anyway, you need to make some crucial decisions about how to rationalise your Source Citations.
It seems you have correctly linked photos of people to the Individual record Media tab.
Now you need to decide where to link the Media images of documents and other Source Citation details.
The question they need to answer is “How do I know this fact happened to this person on this date in this place?”
e.g. How do I know the birth of John Smith happened on 1st April 1900 in London?
Also, what about the other information on say a Birth Certificate such as the parents’ names, addresses and occupations.
Do you want to add Citations for those facts as well?
One option is to add those Media images and other details to each Citation.
That is what many FH users call Method 2 ‘lumped’ Source Citations.
The other option is to create a separate Source for each document and Titled to describe that document.
Then the Media image, a transcript, references numbers, etc, can all be added to that Source record.
The Citations would simply link each derived fact to that Source record but contain very little information.
That is what many FH users call Method 1 ‘splitter’ Source Citations.
There is a companion program called Ancestral Sources that streamlines the creation of Source Citations.
The FHUG Knowledge base has advice for ‘Citing Sources: Method 1 and Method 2’
I suggest you study the options and decide what path to take.
Then we can advise how best to follow that path.