In the most literal sense, I found it gross because I don't want to watch Walt and Skylar having sex.

The "having sex with a severed head" analogy was ripe for the taking. I admire your restraint.

It did show renewed commitment to the cause, but also that he was getting burnt out and his enthusiasm isn't going to last.

Agree - I saw it as mirroring Walt's gross bedroom scene with Skylar in BrBa Episode 1. They both survive crazy dangerous situations through their wits, and gain this slightly menacing dominance/confidence.

"Let's Cook"

It's clearly a way to show that he's mentally ill. This was what the whole "take off the space blanket" scene was about, as well as all the conversations about him at the firm.

I definitely thought it was a phallic thing at first. Overanalyzed the shit out of that scene! Yeah!!

but which one