Hi Nais! I'm Therese, a Skype Independent Adviser and consumer of Microsoft products here to assist you.
I am sorry if you are experiencing this, let me help you. Just so you know, there are three ways to log in to Skype - all depends how you created your Skype account:
1. Your old custom Skype name (not your email address).
2. Your email address (assigned a live: or live:cid prefix alphanumeric Skype name)
3. Your phone number (assigned a live:cid prefix alphanumeric Skype name)
To know if you have multiple Skype accounts associated with your email address/phone number, I highly recommend to follow the instructions below "I forgot my user name for Skype" in this article:
https://support.skype.com/en/faq/FA109/
Note: This process is not applicable if the email address/phone number you used to create your Skype account is no longer accessible.
Let me know how it goes and if you need further assistance, feel free to send a reply.
Kind regards,
Therese`