no tapering advice, but I'm a coach and I just thought I'd suggest you chat with your coach -- via email, phone, or in person -- whatever's most comfortable for you.

I don't know if you signed a contract with your coach when you began your coaching relationship, but many coaches ask for 30 days' notice if you terminate your agreement. if that was the case, you might want to clear it up with your coach.

good luck with your half IM.