We would only use "10 years ago". Use "before" and "after" with an action. Before I graduated from college, I studied everyday.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.
WwwdotcomThen use "IN"
In 10 years,_________.
We don't use before and after. We use other words to match the meaning of what you are saying.