Am I overreacting? Thinking of re-homing my dog..

So let my start off by saying I love my dog very very much and this is not something I am taking lightly. We got my dachshund mix Jackson in January at 9 weeks old. He has been tough to housebreak, but other than that we haven't had any issues. He did well in a crate and was amazingly gentle with my 5 year old DD. Last month we started noticing some things that have me on edge. He is very very attached to me, and has started growling and snapping at my DD while he would be sitting on my lap. Then two weeks ago he started escaping his crate, pooping in his crate (NEVER done this before) and getting more aggressive when we would get home for the day. I have my wonderful mother letting him out in the middle of the day, and he is never out of his crate then. Only in the second half of the day. Well on Saturday he bit my DD. While he was sitting on my lap she had to come to sit by me and he bit her arm. I am seriously considering rehoming him because I am terrified it will only get worse when baby comes.... HELP.