Gyno will fuck with your head, and the more you read (research), the more confused you will be.
You will find lots of information saying that Letro can reverse gyno (for some).
They usually follow a protocol with something like this: Ramp up to 2.5mg E/D, once the gyno is starting to 'disappear', continue with 2.5mg e/d for another week, then you ramp down. As you ramp down, you should take Nolvadex for 10 days, at 20mg E/D for 1 week, then 10mg for 3-4 days.. Something like that.
I've struggled with (and still am) with gyno myself.
On cycle, it always grows a bit, but it is kept in check with arimidex. After cycle, when using Nolvadex for a month, it shrinks.
I've had a hard lump on my left chest for some years, which is now almost gone. But since im a lucky bastard, I got a lump under my right nipple, out of "nowhere" (No cycles involved), that im trying to take care of with Nolvadex. Im currently on day 13 with Nolvadex.. For the first week I did 10mg E/D, then I bumped it to 20mg (I won't go higher).. After bumping it to 20mg E/D, I have felt things getting better each day. So I hope it will continue like this.
Regarding 'puffyness' - I do have some puffyness that just won't go away.. I notice it when im really really warm. This has gotten better as well, but it's not gone. Im not sure it will ever go away either... luckily, it's not that bad. No problems going to the beach / pool or whatever, because my nipples are always hard as hell then
Here is a study regarding Nolvadex & Gyno:
Treatment of gynecomastia with tamoxifen: a doubl... [Metabolism. 1986] - PubMed - NCBI
For some it definately works (or helps improving the gyno you already got). One of the test subjects got a recurrence.. Aromasin / Arimidex 14 days after last Nolva might help against estrogen rebound.
You can also try to get rid of it 'naturally', read this:
16 Ways to Fight Gynecomastia - Primordial Performance Discussion Forums
Basically, it's a jungle out there, regarding advice for gyno. I suggest you try different approaches and see for yourself.
Good luck!