My female cockatiel keeps getting pushed aside?

[*HELLO*]

Recently I got another cockatiel for my male cockatiel twitter. The female cockatiel keeps getting pushed aside in everything though. The male won't let her eat, and keeps barging on her perch whenever she moves to a new one, keeps biting her, so on. Is it just because they are not used to each other or..... And how do I fix it since the female is now kinda scared of him..?

[COUNTRY--GIRL]

Might need to separate the two birds seems the male doesn't appreciate the new cage mate.
Might need to cage them apart, but close enough to see and hear but away from each other to cause any harm.
Besides the male may consider the cage all his and does not want the female around its his territory and shes invaded it.Hes probably showing territional moods and attacking the female to let her know this is my area,he may seriously harm or injure the female with these circumstances...