Re: Losing patience!!!
If you want to gently encourage weaning without pushing it, you can continue the don't offer-don't refuse and add in DISTRACTION. Like mommal said, getting out of the house is really good for this and once that first trimester fatigue has passed that will get easier. In the meantime, you can try to time your outings for 'usual' nursing times. You can also try offering special treats instead of nursing. Things he doesn't get often. It may sound like a bribe...and it is. But it works. And keep in mind he actually may be more hungry and thirsty if he's nursing less (or getting less milk when he does nurse). Make sure he has a cup of water available for when he's thirsty and maybe offer juice or something when he asks to nurse (if you do juice- even better if it's a rare treat for him).
He is likely getting aggressive while nursing because your supply is diminishing. In the past, nursing more forcefully has worked to get more milk. He needs to learn it's not going to work now. When he gets too rough, unlatch him and tell him mommy is sore and he needs to be more gentle or he won't be allowed to nurse right now. Or if you feel that's more than he can grasp, just tell him to be gentle and if he isn't, unlatch him and put your breast away for a while. He'll get it.
And this may not be something you want to hear, but...he will probably be jealous of his nursing younger sibling. Whether he weans now or not. Most kids are. And most ask to nurse again when they see the baby doing it. You can deal with that whatever way you are most comfortable with, but for me it made the most sense to say yes and let her try if she wanted to (I was about 20 weeks along the last time she nursed- she'd just turned 2). She laughed and put her mouth on my breast, but obviously didn't remember what to do. She just sat there for a second and then laughed and jumped up and ran away. She didn't actually want to nurse. She just wanted to know that if she really wanted to...I'd let her.
“We are not put on earth for ourselves, but are placed here for each other. If you are there always for others, then in time of need, someone will be there for you.”