How is Jesus God

Hey, I know this reply is rather late, but still I hope I can answer your question.

I am a new Orthodox Christian, currently a catechumen and I was a muslim before.
The Trinity and other concepts are quite hard to understand and there's countless analogies out on the internet, but I need to stress that no single analogy does the concept justice and that you can often be misled.

The logic of the Trinity:

1. The Father is God

2. The Son is God

3. The Holy Spirit is God

4. The Father isn't the Son

5. The Son isn't the Holy Spirit

6. The Holy Spirit isn't the Father

7. There is only one God

The Trinity is made up of 3 persons, these persons are distinct, but can't exist without the other. Something like us humans, we are made of bones, flesh and brain/soul. None of which can exist without the other. Or we can also use mathematic examples 1*1*1=1, 1/1/1=1 - always ONE GOD.

There's also 2 natures, divine and human. Jesus was both truly man and truly God. And as you know, he was sent to the Earth to die for our sins because we are not able to not sin, only the Son (Jesus) was able to be sinless. You can also see the symbolism of the two natures in the Christ Pantocrator icon.

The coming of Jesus was prophesised even in the Old Testament (Micah 5:2, Isaiah 7:14, Zechariah 12:10, and many other verses). Also, Jesus himself declared in the NT that he is indeed God, in John 8:58 he said: "Before Abraham was, I am." which means that he's been ever existing (= he is God). 

I will share with you some helpful links:
https://www.saintsophias.org/the-holy-trinity.html
https://www.logos.com/grow/analogies-for-trinity/
https://en.wikipedia.org/wiki/Hypostatic_union
https://www.gotquestions.org/second-advent-Messiah.html
https://www.oca.org/orthodoxy/the-orthodox-faith/doctrine-scripture/the-holy-trinity/the-three-divine-persons

If you want to talk more about this or if you have any other questions you can somehow contact me through this app or on Discord: .theral or maybe even instagram: hurskyym

I hope I helped you understand the rather difficult concepts. God be with you.