I checked extensively and yes, there are obstacles to the retreat; it seems difficult. So I checked and according to my observation you have life obstacles. If you can:

• Take the long-life initiation of Amitayus. If you can, take the initiation four times, so this means the lama giving the initiation does the visualization and puts the torma on your head four times.
• Liberate 80 animals. Use my book, Liberating Animals, which explains the practice. Liberate animals that are otherwise going to be killed.

When you are doing the Vajrasattva recitation that Chöden Rinpoche has advised, you can still meditate on lam-rim even during that time. For instance, you can do a little meditation on Vajrasattva, then recite the mantra (some long and some short) and meditate on lam-rim while you are reciting the mantra.  

So try what I have advised and finish what Chöden Rinpoche has advised. Also, I checked and it comes out very good for you to do the Masters Program.

I am making prayers for you. The essence is to make your life most useful, so you must study the lam-rim, meditate on the lam-rim and actualize the lam-rim, develop guru devotion and live your life with bodhicitta as much as possible.

With much love and prayers...