Urgent!! Membership plugin locked me out as a super admin!!

When using my only admin account I have, tested the subscriptions page and clicked to upgrade to a free account. Now I don't have access to all of the admin dashboard stuff. I'm locked out!

I can't disable the membership plugin, or anything because I do not have access to that section. I also can't delete the plugin manually because it will mess up my website which is already publically available, and I don't want to lose all the subscribed members, settings, etc.

Please help! I think WPMU dev support is still active (activated it yesterday) from another issue, but it doesn't have much time left over so this is definitely a time sensitive issue!

Please help!