The 1/20 Training plan

For those looking for the perfect train plan - this isn't it! However I'd like it to be. I've been riding for a little more that a year. Set my own training plan with the pitiful amount of knowledge I have but wasn't able to achieve my goal. Now seeking assistance. Have a good base of about 300 km per week. The week has been looking like:

Monday: run 5-8 km
Tuesday: ride to work 36km doing intervals something like 3 min on 3 off or 30 sec on and 4.5 off or 2x10 min
Ride home at variable pace throwing in some hard efforts.
Wednesday: run 7-12 km or ride or both
Thursday: similar to tue
Friday: Ride to work steady at about 28-39km ave
ride home sim to tue
Sat: hill repeats for 1.5-2 hrs 700m at about 5-6%
Sun: about 100 km Beach rd with everyone else. Usually pretty hard

PB for 1/20 is now 16.04 but I really want to break 16. Would love some tips to improve training