Hi,
I would suggest that you re-launch your old blog. It would prefer not to call it a re-launch, rather it is sort of a re-branding.
Here are few steps you might consider taking.
1. Update design. Consider flat and thin approach
2. Integrate social media
3. Start generating new and interesting content
4. Re-activate your social accounts
5. After having done sufficient amount of work, shoot an email to your list and friends as well. Let them know that you are back in town.
6. Devise new SEO plan and continue implementing.

There can be many more small things but I just wanted to give you some encouragement. Remember, it is always better to work with old domain.

It is a matter few weeks only when you will start seeing good enough improvements.

Regards,
Fahad