Advice? (aggressive dog)

So my husband and I got our pup when he was 2 months old. We already had one dog, a 7 month old. She was perfect, so we thought, one is fun, let's have 2! Well, it was pretty obvious right away that he had not been socialized hardly at all, and he may have also been abused. We looked up ways to help him feel more comfortable at home with us, and in time he got better. He is almost 1 year now, and his energy level is uncontrollable. Even when we take him out, he is crazy at home. I know we should have expected that (he's a red heeler) but our other dog doesn't have the energy to play with him (despite being half heeler) and so he is crazy. And whereas he is not aggressive toward my husband and I, he is to strangers. I can't take him on walks, beecause he looses his sh*t when he sees people. He gets into fights at the dog park, and is too hard headed to quit. My husband and I are TTC, and I know he won't likely calm down any time soon. I am worried about him with a baby, his high energy makes him careless. He runs in front of me and I almost fall, he took my foot out from under me once when I was going down the stairs and I fell. We have talked about taking him to a shelter, but I worry they will put him down (aggression to strangers). We tried rehoming him ourselves, but again, even the nicest people he would snap at. He has not drawn blood on anyone (save when he was a puppy, he attacked my husband once in thinking he was going to hurt him). I really don't think I can handle him when we have kids, but I don't think I have the heart to take him to a shelter either. It is a no kill shelter, and they reform dogs who come in from bad situations. However, if a dog can't be "fixed" they do put them down. Idk. Has anyone else been through this? Any CONSTRUCTIVE advice is welcome. This so him. He's a cutie :) And he loves our kitty haha.

Thank you everyone for the responses, a trainer might just be what we need. For those of you who have had this before, what types of jobs do you give for your dogs to keep busy? Part of our problem is living in a townhouse, and my husband and I both working full time. Which is why sometimes I think he'd be happier with someone more equipped to handle his energy. However, if there's a way we can still handle it with the situation we are in, I would prefer to do that.