Peertube?

The ideal platform is Funkwhale, in my opinion. It is a part of the fediverse. Peertube is also a good option. Apart from it, you can find an aggregator, who can post your music on many platforms, some options are LANDR, CDBaby etc. But they charge some fees. I have published my music using Symphonic Distribution. I have registered as a record label there and have published music by many artists. Some aggregators also do that content ID thing on YouTube.

I was thinking of Mirlo and Funkwhale but there are even more here:

https://forum.wedistribute.org/topic/16/current-fediverse-resources-for-musicians

Castopod might be cool, it’s mainly for podcasts but might work for you as well?

Just get some cheap web hosting.

Off topic, but I tried out Vocaloid. Pretty neat package. Does have a learning curve to it, but yields some pretty impressive results. Have you looked at Landr or perhaps Bandcamp?