I am conflicted between getting a second master's and moving on to a PhD?
If it is possible to start your dream PhD without further prerequisites: do it. Also take notice that it'll be hard, but doable. In my opinion a second Master's has no benefit, taking the possible admission to the PhD program aside.

I know someone, who got a PhD in physics after a Master's in biology. I went to a PhD in CS after a Master's in mathematics.

(This is also a bit dependent on the field and on the social component, so please tag with a country for further answers. My experience references German system, but it should be generic enough for US too.)