Help me understand how to help him

My partner and I met each other while we were both married, we both took the steps to end our marriages. He has 2 very young children that he is crazy about. They are only 3 and 6. He will ensure that he spends every moment he can with his children at any given opportunity. He is an amazing father and never wants to miss a moment. He told me he loved me before we ever had sex and we talked with our spouses about breaking up long before we ever slept together. We engaged in a whirl wind romance talking nonstop and texting constantly making every effort to be together. November he moved to his own home and he started to spiral into silence and depression. I was very upset over this as I just did not understand what was happening as he grew more and more distant. By new years eve we rekindled and then next 3 months where spectacular. We spent every weekend having wonderful dates and lovely evenings together. About 3 months ago he started with drawing, I let him know I felt neglected and he told me that his separation has hit him hard. He is sad about the kids, he is missing out on firsts and events but he is not pining for his old life with a spouse he did not see a future with. He said he just wants to be alone and cry. He said he even thought about suicide but would never leave the children. We have not spent a night together in 3 months not have I seen him in 1 month. He is distant and sad and not himself. He said he misses Us and wants to feel like himself again and support me like he used to. He was so unbelievably supportive and positive before. I know space is clearly what he needs. I am reading up on depression and what to say and be as positive as I can. The last 3 months I spiraled into a sadness. All I did was cry and I finally turned a corner and decided to be strong for the both of us. I guess I am just wonder what others have experienced or could give me some advice….. I feel this will get better with time I just dont know what to do in this situation and want to be helpful instead of hindering the situation. Thanks so much