DeeCee, intense time. You take as much time as you need to do your grieving. And then, yes, you do need to move on. But first you need to find the strength inside you and that doesn't happen in a day. It sounds like you've got a great medical team. And that you're very comfortable in your surroundings...which is VERY good.
I found journaling helped to find the strength needed. As did plain old daydreaming...which I still do a lot of. I can't say I used any meditation techniques but I focussed on God...a lot. And that's what got me through the most. Giving myself permission to think about me and treating myself like I'd treat someone else in the same boat helped...bunches.
Having raised 2 kids of my own, 1 foster, and numerous exchange students, besides being the main caretaker for 3 of our 4 parents and being self-employed, I wasn't too used to thinking of myself first. And I'm sure you all can relate. Women tend to focus outwardly on the needs of others and feel...guilty?...when focussing on themselves.
So if there was ever a time for you to take care of yourself, this is it. Your doctors will appreciate it, too, as you respond...better...to your treatments. But you sound like you all ready know this. Please take my words as just further encouragement.
I also had Stage 2, Grade 3 cancer. No lymph node involvement but skin involvement and 4.5 cm tumor size. I was triple negative (estrogen negative, progesterone negative and HER2 negative) though.
There was a history of heart disease in my family but I had one round of 4 cycles, 3 weeks apart, of AC and then a second round of 4 cycles, 3 weeks apart, of Taxotere. The MUGA scan that was done on my heart prior to chemo showed there shouldn't be a problem. And thankfully, my cardiac stress tests since are still good. All my chemo was neo-adjuvent (prior to surgery) so it's been 4 years this month since they were begun.
Disney World is the best medicine for all ills. I went twice during chemo and found no problem getting around. It's so handicapped friendly and scooters are a blessing. Granted, I wasn't flying all over because I was pretty tired. But I still hit as many rides as I could. It was hoot seeing the faces of the CMs when this bald, old lady drove up to the Single Rider line of MS or TOT. I'm sure they wondered if they would be carrying me off...or worse, cleaning up after me

For the record, neither happened. That's the wonders of modern medicine.
BTW baldness at WDW is a badge of honor. You can't believe how supportive everyone was...from CMs to ordinary people. And there are a lot of us Disneyphiles who share this boat. I'd meet other breast cancer survivors everywhere I went. When I first learned of my cancer, it was very shocking. And I wasn't too sure I liked being known as a Breast Cancer SURVIVOR. Now, after meeting so many strong women, hey, I boast of my survivorship. We're tough ladies and deserve to have it known.