You will need to build a reputation and demonstrate your association with the charity you want others to support through your account if you want any kind of significant contributions. If you spend the next 11 months building your account with quality content, you may be able to fund the 500 HBD yourself, and earn real support. Your reputation has taken a hit, but it is still in positive territory, so you have time to build it back up.

Don't focus on the numbers. Focus on what you can control: creating the highest-quality original content you can, and honestly engaging with the content others create. Let the followers and upvotes find you at their own pace. Don't expect to be an overnight success. Don't beg for follows or upvotes. Let go of such concerns, and instead work toward being worthy of such responses.