First, sorry to hear about the spread to the lymph nodes...if there's any good news, it's that there is no involvement of the bones or organs based on the scan,

Now, next question, what to do...?

More and more data indicates treating the entire PLNs system with radiation and adding ADT, six months generally though some studies indicate 12-24 months. I believe the more common approach is six months. The radiation treatment plan will call for 25 or so treatments, 45 Gya, with boosts to the identified sites and wider treatment margins around them.

As to the side affects of Lupron, yep, you can read all about them...the question is which ones will you experience and the severity. If you are familiar with statistics and the Bell Curve, question is, which ones will you experience and how "severe?"

I was on Lupron for 18 months, side affects I experienced:

Hot flashes.
Genitalia shrinkage
Fatigue, mild
Muscle and joint stiffness.

What I did not experience:

Depression
Loss of libido.

After I stopped Lupron, testosterone came back and all is "well."

You may want to discuss with your medical team an alternative to Lupron: https://www.fda.gov/news-events/press-announcements/fda-approves-first-oral-hormone-therapy-treating-advanced-prostate-cancer

It does not have the flare associated with Lupron, has a better cardiovascular side affect profile and testosterone is quicker to recover when you stop. Depending on your insurance, may be more costly.

Throughout my time on Lupron I continued exercising, travelling, more or less my normal life. Some of the more humorous things were not using the heated pool at the gym, not running the heater in the car, going out on the back deck in the dead of winter...

Given the spread to the PLNs, doing nothing may not be an option. If you and your medical team agree, then, question is what do we do...monotherapy is not necessarily the best option, doublet therapy may be a better choice in terms of a longer and more durable "remission." Note I don't say "cure" since the prevailing theory is advanced PCa is not "curable." I went with triplet therapy, adding taxotere. I did that because of the aggressive nature of my PCa. Depending on your clinical data such as doubling and velocity times, time to SRT after surgery...