You had good results with the pen you spoke about? How many times a week do you use it and where did you get it from - can you give a link?
1.5mm needles sounds scary and painful. The same Amazon web site said up to 1mm is okay if not using minoxidil. So I'm a little wary about going higher than that.
It really varies case by case, and different surgeons have different opinions on the matter. Generally speaking, it seems most surgeons would recommend taking Finasteride in conjunction with a HT, but by no means is it a deal breaker. I took it on and off for a couple of years (started at the recommendation of Dr. Mohebi) but stopped a few years ago due to mild side effects. I've managed to hold up just fine without it, but that's not always the case.
Your hair still looks considerably better than before you started the Finasteride. Fingers crossed for you that it shapes back up to how it was before and this is all a temporary shed. Regardless, there are still other options it seems like you can explore, so not all hope is lost... And stay focused on the progress you've already made.