How do I delete my Game Development Stack Exchange account, specifically?
You will need to involve the community team to delete your Game Development account. Instructions for doing so can be found here. Be sure to specify that it's only your Game Development account you are interested in removing. The community team will work with you from there.
I'd be curious to know more about your reasons, though. From my perspective this desire seems rather abrupt.
I am assuming you mean you wish to delete your account. The only thing close to "unsubscribe" would be 'unsubscribing from emails', but your mini-rant suggests this is not what you want.
Given that you have made posts on the regular1 site, you can not simply delete the account, yourself.
If you have voted or posted, please contact the Stack Exchange Team:
Visit the contact form and select 'I need to delete my user profile.' After you contact us, the team will reach out with further instructions.
Please take this with a grain of salt: In the real world, people are going to disagree with you. If you throw in the towel over one or two people disagreeing with you, especially when there is evidence of many more users trying to help you, your going to have a bad time.
In game developing, your going to receive criticism, too. It is important to be mature about this sort of thing. Criticism can reveal key issues in your game, but your reaction to criticism may reveal key issues to others.
1Regular referring to the non-meta site