Rehoming a dog, am I making no the wrong decision?

I never thought I’d be this person. After 7 years of owning our golden retriever I think we need to rehome him. I used to be one to bash other people who rehome their animals. After having a baby, our golden retriever has become aggressive, possessive, and howls nonstop like he’s in a trance every single time our now toddler cries. I can’t take it anymore. We have worked with trainers, but unfortunately didn’t see much improvement and we can’t give him the effort and time. We cannot relax in our home because I’m constantly monitoring and keeping separate the golden from my toddler to avoid him getting bitten. My other dog, a border collie, has no issues. I think it’s the right thing to do to rehome the golden to a home where they can love him and give home time, but I feel extremely guilty. Will our dog be depressed? Will he miss our other dog? Will our border collie become depressed without him? Will I regret rehoming him later on? We plan to have more kids so this phase is going to take a long time. We found a reputable Golden Retriever rescue in our area that will take Goldens and find them a safe and loving home, but I still feel so guilty and ashamed. Any advice?