Greetings Maria
It is good that you have asked for prayer, we should never try live through these issues on our own.
It is clear to see Maria, that you love him, you really care for your relationship and for what your partner is going through.
You say he is suffering depression, I have been through depression to the lowest of lows, it is not a pleasant place to be for sure.
May I ask Maria, are you married? And regarding your partner, is he born again also, and is the depression he is suffering from due to relationship issues, work or other items. If you feel it hard to say, or do not want to I totally understand. Knowing helps us pray together, sing off the same hymn sheet so to speak, we come into agreement together, in faith, and as the issues at the Lord's feet in prayer.
Br. Bear above has given you some helpful advice, no matter what the situation we go through, get right with God, this is an important foundation often starting with opening your heart to God through Jesus, repenting of the errors and submitting to God in Faith.
I nearly lost my wife and children due to my faith, it was so close, I share what I was told and it works, but it takes time. God's speed.
No matter what you go through, love one another as Jesus loves us, never argue, let the peace of God teach your heart and lips, I am not saying you argue Maria, but just mentioning to avoid it. In all you do, share your God given love, let Christ shine from you, He is the Light of the World. Also try talk together, ask and listen to what he is going though and trying to cope with, let him know gently what you are going through, share in love.
In all you do sister, have Faith, remain hopeful, and love him always. The greatest of these is Love.
Trust in the Lord always. He will guide your path.
Love brings healing sister, please do keep in touch, Jesus loves you we do too.
The following scripture helped me in those very hard times. Romans 8:28
Bless you