I mix fed both DS1 and DS2 so it's doable and I bf both of them way beyond a year. BUT, it does cause your milk supply to decline.
I started mix feeding because I lacked the confidence that my baby was getting enough milk. It meant that DH could give a bottle and I could get some housework done or do something with my other child. On the downside, I had the added hassle of sterilsing, preparing formula etc as well as the decline in my own milk supply. With DS2, I returned to exclusive bf when he was 5months old, but it was very, very hard to reestablish my supply at a time when bf should have been easy.
So mix feeding can be done and I know of quite a few women who bf but give 1 or 2 bottles a day.
BUT, I currently also have a 9 week old who is exclusively bf. I have more confidence in my abilities to bf now and have "ridden out" the extremely hard early stage. I think you should wait a while before deciding to mix feed because you are nearly at the stage where bf becomes a doddle (about 3 months or so)and you probably won't want to bother bottle feeding when you reach that stage.
I think it's normal for your breasts not to feel so full at this stage. As for bf in public; I bf DD in a window seat in MCDonalds on our busy high street on a Saturday morning. Noone turned a hair. The more you bf in public, the more confidence you will have.
Sorry, am waffling now - should really go to bed but wanted to give you some sort of reassurance as it were.