Today I went to the pool and did some underwater swimming with no wetsuit, weights, mask or fins. (With swimsuit though.

)
Only a few metres at a time, because it wasn't a freediving session, and the pool was only about 1m deep.
It was very good. I liked it so much I didn't want to get out, but eventually the chlorine became too much.
I also got away with holding my breath in the spa pool, which is very warm. Of course it was only for a few seconds at a time. The lights in the sides of the pool look magical.
Definitely worth trying again.