Yes, it's hard to conceptualise, but equally, it is simply not correct to say that God the Son = God the Father. Each person of the Godhead is fully God in their own right, yet they remain distinct persons within the Godhead.
Bearing in mind we are considering the very nature of God, it would be passing strange if it did not present a real challenge to our feeble minds, even one with brain cells to spare. Like mine, for example.
I think it was Metzger who said that the phrase 'God is Love' would be meaningless unless He eternally had someone to love. There is only one possible candidate for the object of His love - His one & only Son.
If you accept the jehovah's witnesses doctrine of god, you must believe god was a narcissist, coz there must have been a time when god was on his own, so he had no one else to love except for himself.