I think it has been touched above, It sounds like both of you are suffering from depression. Go and speak to your doctor, even if you don’t want medication they’ll point you in the right direction to get help.
I can only speak from my experience, going to talk to my doctor and consequently seeing a counsellor helped put things into perspective. Also saves posting personal stuff on sites like this.
If you still feel the same way, get some legal advice. As mentioned above, It’ll be years before you are rid of the emotional and financial ties, so will need to be done properly. Or you’ll get properly screwed as the law almost always side with the mother on breakups.
Good luck, whatever you decide on.