obedience class to start.
any dog needs to know where they are in the pack.. yours.. does not.. if you can this is where i would start.. it is a fast way to get him trained and it will be a good thing ( he will get to get out and feel he is doing something! ) for the dog.
big dogs need to be walked ... 8 months pg. you can't do that.. but.. you can get on your coat.. and take 30 mins outside with him..
I have a feeling he isn't good with playing catch.. good at getting the ball. not so good at bringing it back.. the obedience class will help with this.. never run after a dog if he has something that you want.. only teaches the dog that he is higher up then you.. so .. if you throw something let him get it.. and sit down and let him do his thing with it.. mostlikelyhe will run around the yard a lot and wont listen to you if you call for him. which is fine.. the fact that he is running is a good thing!! he needs to get all this energy out.. if you can do this twice a day that would really help him with his anxiety.
which is what it sounds like he has seeing as he is eating and destroying things... which is common for dogs that are bored
now.. you are 8 months pg.. a baby very soon on the way!! and a dog that doesn't behave.. I can't even imagine.. if you feel "guilty" about giving him up.. please do not..it is better to give him up to a good home then you and the dog being misserable.. sometimes youhave to make hard choices.. and gosh.. this is one..
getting the dog "help" will take a long time.. finding a good home not as much time. and this is a time sensitive issue..yes your dog is part of your family.. but.. sometimes.. it just doesn't work out
((Hugs))
btw.. he is really cute!! we are hoping to add another dog to our family..just.. not anytime soon!!! lol gl hun