Looking for a Century Training Plan

I need some help -

I am looking for a century training plan to help me reach my goal of riding a very hilly century in October. I'd like it to be heart-rate based and I'd like it to last between 12 and 18 weeks. Right now - I'm just getting back into cycling (I've ridden a century before and I'm an ironman so I have been used to going long) and I'm big (250) but I've worked up to a 20-mile ride and I ride 10 miles every day 5 times a week. One of my major issues is that I'm slow - I average 11 mile an hour so I need a plan that will develop my speed as well as prepare me for the hills I will face in October. I've tried BT and Training Peaks but I haven't found anything that really fits my needs. In a perfect world - the training plan will be detailed enough for me not to need a coach.

Thanks in advance for your thoughts!

Edited by Qua17 2020-05-31 4:31 PM