Welcome to the Wefugees community!
As for your question, there have been plenty of similar questions which were already discussed on our platform, please have a look at the following threads :-)
Can my partner and I apply for asylum in another EU country if our asylum claim gets rejected here in Spain?
Can I apply for asylum in Germany after been living in Belgium?
(If you search for "Dublin or Second asylum claim" using the search bar on the right, you will find even more questions & answers)
Unfortunately, Dublin also applies if you withdrew your asylum claim - what counts is that you entered Belgium and applied there in general, and that they took your fingerprints. There is a way to claim asylum again that you can read about here:
Claim asylum for second time in EU
I hope I could help. Feel free to reach out to us again if you need any further assistance!
All the best,