The OP needs to cover 150km on flat surface within 12 hours. It's the average speed of 12.5 km/h.
Even if we are more realistic and allow for one hour break every 2h15', we end up with four stages of less than 38km each to be ridden at the average of less than 17km/h.
If we put some challenge into the event and, let's say, set on the average speed (excluding stops) at 20km/h, we are talking about riding for 7.5 hours effectively with the total of 4.5 hours of breaks. And 20km/h on a modern road bike on even surface is "walking pace".
For someone that does 45 mins jogging every day it's totally doable, however certain conditions apply.
First of all make sure that your road bike is properly fitted, i.e. the handlebars are not too far from the saddle. On the weekend have a 50km ride within 2 hours. Check how you feel (muscle pain and lower back pain). The very next day have another ride for 50km in 2 hours. Do you experience muscle pain? Work on your nutrition. Lower back pain? Bike fitting needs to be improved (most likely your stem is too long forcing you to stretch too much). Any other pain? Work on your position. Repeat every weekend until no sufferings on the second day occur. You have 7 iterations, that's a lot.
Make sure the gear you have is 100% in order so you don't loose time on technical stops. If no on-the-spot technical assistance is provided during the event, provide yourself with one. What I'm using is:
- spare tube
- bicycle pump
- tyre patch set (check if the tyre rubber solution is not expired)
- dog bone wrench
- basic mutlitool with chain break device
- spare master link for the chain (I discourage you from using power link as it needs pliers for disassembly), should your chain break in the middle
- latex gloves in case you need to perform dirty fix and you don't want to ruin your handlebar wrap
- ductape (1 meter strip wrapped around some object, even bike frame)
Except for the pump and ductape you can easily fit the rest under the saddle in a saddle bag.
Use proper clothing, i.e. padded shorts and cycling jersey (large pockets on your back), helmet, gloves and sunglasses. Don't forget sunblocker, you don't want sunburns ruin your day. Ride "naked" - the underwear will make your sitting parts sore very quickly.
On the day of the event take good care of proper nutrition. Slow carbohydrates for the breakfast will give you strong foundation for the whole day. For the race take some power bars or ginger bread snacks and a lot of hydration (e.g. isotonic drink in tabs that you will dissolve in water topped up as you go). Eat regularly, even if you don't feel like. The same for drinking. And don't check the current results too often. The more frequent you check your distance the slower you go, perceived.
Why I'm writing this? Last weekend I've ridden Eroica for 160km. I'm not an athlete (my BMI is around 27, fat percentage around 18%). For the past 5 years I was jogging 2 times a week on the average, distances between 5 and 12 km. The longest bicycle trip in one day was less than 100 km.
My preparation for the event (except the technical details I've described above) during 2 months prior to the event was:
- ride between 50 and 60 km once a week in less than 2h30'
- do running exercise for 45mins once a week
One week before the event I did 2 consecutive days riding which went well.
I rode the route in less than 8 hours of effective cycling and in 11 hours total (scheduled stops on the route and technical difficulties) with the average of 19.9km/h. Eroica consisted also of unpaved roads and 1567 m elevation gain (measured by strawa was more than 1800).
And I could easily ride 20km family ride the following day.
You training schedule is ok, have couple of test rides of 50km and good luck!