At what point do you become a weeb if you like/love anime

Depends on what weeb means:

Usually when weeaboo was first used it was to describe one who was obsessed with Japanese culture and declares themselves Japanese. Also, they usually tend to disrespect the culture either due to a lack of knowledge/ history or plain right ignorant about customs.

Today's meaning is now used to describe someone that wants to visit Japan, loves anime, and loves Japanese culture.

A good point when you think you become a weeb (todays meaning) is when you are interested in the language and culture of the Japanese.