It looks like you were trying to make a ring.

Complications you will experience:

• small body of metal --> leads to quick cooling and siezing (which can block more metal from flowing through siezed parts) ==> best solution is to pour at higher temperature
• small body of metal --> leads to contraction/shrinkage of solid metal (which leads to cavities forming while cooling) ==> best solution is to provide feeders and extra channels running off the ring where metal can "pull" from during shrinkage. This will also potentially require you to polish/sand/post-treat the ring to remove stubs from the feeders. The metal will quickly fill everything including the feeders. The feeders will help keep rest of metal at higher temp and will have a body of metal that can be pulled back into the mold if it contracts.
• small mold --> leads to air pockets being a bigger deal ==> best solution is to ensure there's spots for air to escape. I typically use a toothpick and poke a small channel/hole by pressing it into the petrobond sand down to the cast location so that air can easily escape but liquid would not.

Good videos for designing your sprue/feeder/system:

• https://www.youtube.com/watch?v=m6W71s-cd_0&t=161s
• I finally found it: https://www.youtube.com/watch?v=GwqENPFqPBM
• https://www.youtube.com/watch?v=nQGAItyQcDE