I'm in a vaguely similar boat. Electronic Engineer, doing low-level software for the last decade, and now having to pivot to more web stuff, because there's little other work where I am. And yes, also in mid-thirties.
Might be interesting to talk f2f if you're local?
I am kind of approaching this from the opposite direction (looking for lower level stuff, but not really embedded either)
I think there's an opportunity for knowing both (IoT, and things like that), but definitely more action on the web stuff in general.
Might be interesting to share tips and strategies. My email is on the profile.