Please be wary of the blog Otherkinhelp!
Otherkinhelp has helped spread misinformation; supports and ables violent ideas, tendencies, and actions; draws personal lines in the sand for what they will and will not help with (which is rude and something a help blog should not do); and uses some very odd psychology when answering some asks.
All-in-all, it's an unsafe place to go to with questions, especially if you actually do need help or have an urgent problem.
If you do need help, however, there are safe blogs that you can go to!
Therian Help Desk is a therian-specific blog run by 3 mods who have all been in the community for about 10 years. Together, they have nearly 30 years of experience with the community and the ins and outs of being a therian.
Otherkinavenger (hey, that's us!) is a broad-spectrum blog that's available to help all kintypes, theriotypes, and groups alongside otherkin such as lycanthropes, vampires/vampyres, starseeds, etc.
Kinfood. If you're hungry, have a craving, or just want your diet to reflect your kintype, kinfood is like a giant otherkin recipe book. If you want something specific they don't have, they also take requests!
While the vampire support page isn't on a Tumblr blog, it could probably be helpful to vampires who need it, or who can't find help within the otherkin community.
PLEASE be careful when asking for help on the internet. Always use your common sense and don't take any advice given at face value-- always do your own research before coming to any sort of conclusion.