I purchased a single user license, then i purchased a 5 user license then another 5 user license, Following the 2nd 5 user license, my first 5 user license stopped working? I used the same email for all my purchases?
While you did not post under an account that has any purchases for me to check, what does 'not working' mean - that they are prompting for activation perhaps?
When using multiple keys, its best to use the email + key for activation over email + password as 'the system' has to make decisions when using the former if you are hitting max activations.
You can see all your keys and activations here:
You can also free up unused activations (dead PC and the like):
Stardock Product Lifecycle Manager