Er+ her2+ poor response to chemo?

I was dx in June at age 31 with er+ (100%) and her2+ (100%) IDC. On some imaging reports the tumor measured 3.1 cm but I know I had another that showed 3.8 cm. All imaging showed clear nodes, but sentinel node biopsy ended up having one node with 2.5 mm of tumor. Did 6 rounds of TCHP followed by lumpectomy and axillary node dissection with the intention of just seeing what the results of the surgery were to further determine whether or not I'd need radiation prior to dbl mastectomy.

The lumpectomy and alnd showed tumor shrunk to 2.1 cm and had no further node involvement (7 removed during this surgery for a total of 9). I've asked for the pathology of the remaining tumor (just out of curiosity) so that has been sent off and we are waiting for the response. My surgeon said because of my age and "poor response to chemo", the radiology oncologist is recommending radiation prior to the dbl mx, which is only going to leave me with the diep flap option for recon (which concerns me because I am quite thin, but the ps thought he could do it). And my margins weren't quite clear, as there was some DCIS close to the edge, so I'm having more surgery (sometime in the next week or two) to get clean margins prior to starting radiation.

The "poor response to chemo" is really weighing me down. I'm glad I didn't have any additional node involvement, but the "poor response" comment has me feeling so discouraged. I just imagine cancer cells breaking free into my blood during treatment due to the lackluster response and now it's just a matter of time befor it pops up again somewhere else - and then I'm out of luck since I didn't respond great with TCHP. This is all just still such a shock. I have two very young children and I've always been totally healthy. Being repeatedly told I'm "so young" with a "very aggressive" cancer is all so discouraging.

Did anyone else have what was considered a poor response but go on to not have a recurrence after surgery?