Are you willing to provide a transaction id? You'll lose some anonymity, but I can probably advise you a bit better on it. PM if you like?
Scratch that, found your previous post.
So your transaction was about 15 satoshi/byte. Definitely on the low side. Fees have been relatively low in the past few days (30 sat/byte), but not that low. They seem like they're going back up now, and it is anyone's guess as to whether they'll stay low-ish or even drop again at the weekend. A difficulty change is about to happen in the next day or so which will slow blocks down again.
Right now, it looks like a RBF to 200 satoshi/byte would get you into the next block. You are welcome to try for lower first or wait it out and hope that it drops to similar levels at the weekend.

Segwit won't magically help you with lower fees in this case - The discount applies when sending coins from a segwit address. These addresses start with a 3 (or bc1 in other wallets) rather than a 1. It would definitely be beneficial, going forward, to send the coins to a segwit address. Assuming you have an up to date Armory and Bitcoin Core setup, you can generate segwit (P2SH-P2WPKH) addresses inside Armory.

You are correct on the purpose of RBF, as far as I know. I'm actually ignorant as to whether you can bump the fees and change the output to a new segwit address in a wallet that you control. That'd be the ideal thing to do though.