Some questions about the Lower registers of the voice

[Chavie]

Normally when singing as of late, i seem to bottom out around B2 OR Bb2

but i have recordings of me in the past, hitting as low as a E2... which i cannot do right now, if my life depended on it ?

On a side note i'm singing higher then i ever have before...

Could singing mostly in head voice all the time, have decrease my lower end ?

Also is it possible to Expand lower range ?

or is that strictly genetic?