Talk with her enough to ask that you go to marriage counseling (even online) with a therapist trained in couples sex therapy. This book resonated with me: https://www.amazon.com/dp/B008JHXRGK?ref_=cm_sw_r_mwn_ts_KHQ6C1FV3Q2H9JVHWCK0
Laurie Watson Wanting Sex Again: How to Rediscover Your Desire and Heal a Sexless Marriage
Be strong man and give it a chance. I'm sorry for your pain.
I just want to say that this is terrible advice. Agreeing to have sex once a week whether you're into it or not 1-literally the recipe for creating sexual aversion, 2-eliminates the need to learn to "flirt".....so her need is just blown off, 3-is NOT conducive to the kind of sex where each partner is highly attentive to what feels good for their partner.
OP should book an appointment with a licensed sex therapist. Or read something like Wanting Sex Again: How to Rediscover Your Desire and Heal a Sexless Marriage https://www.amazon.com/dp/B008JHXRGK/ref=cm_sw_r_cp_api_mEgWFbV3DGJG1?_encoding=UTF8&psc=1
OP - your wife wants extended foreplay that (probably) starts out as NOT PHYSICAL. send texts. Notice things she cares about. Think about her when she not in the room.
Saying you don't know how to flirt is a huge cope out. Just start. Try things. See what lands. This is called walking through open doors.
If you do happen to alternate who initiates, it's f'ing annoying to have your HL initiate sex the first day he possibly can every f'ing time.