You wont be ok unless you realize what exactly is happening to you. Verbal abuse is just as bad as physical abuse. If someone tells you you're something enough times, you'll start to believe it. And with controlling people, it''ll be the worst traits imaginable that they try to project onto you. You'll believe you're' selfish, stupid, ugly, a whore, a mooch, and whatever else they're messed up heads come up with. The irony is that the person saying the terrible things most likely doesn't actually believe what they're saying. They're main objective is to control you. By tearing you down and making you feel worthless, they're hoping to eradicate your confidence. Without confidence, you lose your will to simply have any kind of opinion on any matter. You'll lose yourself and become a shell of a person. What replaces what you lost will be your brothers desires.
What you need to know is that although he may care about you in some twisted way, to him, his needs will always come first. Don't be fooled by his niceness. It's just another way to get your attention. Verbal assaults, physical threats, guilt trips, kindness: none if it has any real substance. None of it is true. Truth is irrelevant to the abuser. The the only thing relevant is control and that's the only thing any of these modes serve. Don't believe any of it.
I've been through this. With a girlfriend and a brother. I know how much a harder this situation can be when you're dealing with a close relative. With an SO. you can leave them and will most likely have the support of you're family and friends. But when it comes to siblings, both family and friends will say "but he's your brother". FUCK THAT. Nobody has the right to ruin you the way he is attempting to.
The best thing you can do right now is what you already did. Show your mother the text and tell her everything. More than likely, you're brother will try to put some distance between the two of you because his method isn't as effective if you're not isolated. My brother would call me a mama's boy when I tried to include her in on what was happening. It was his attempt to isolate me by trying to make me feel like less of a man for reaching out to my mom for help. Once your mom knows whats happening, he'll probably feel like he's losing control of her too. The abuser knows what they're doing is wrong so they really don't like it when other people are in on their dirty little secret. This is why they're so charming to others. So it would never even occur to them that they're capable of what they are doing.
Hopefully, after he loses control of your mom, he'll resort to his abusive name calling and she can see that side of him. Thats what happened in my situation. I had to move in with my mom for a few months after a room I was renting was flooded. She saw a few situations escalate from start to finish and saw that he would look for the littlest things to berate me about. That he was hell bent on making believe how terrible of a person I was. She saw how baseless and irrational his arguments were and he didn't like that one bit. He ended up saying terrible things to her and thats when finally became clear to her.
I just turned 33 and I wish as was as smart as you are at your age. You've recognized something is wrong and you're doing something about it. Stick to you guns. Get your mom involved. Make sure she's aware of everything. Do some research and get her to do a little as well. You have some hard evidence in those text that can affirm the signs of abuse that you'll find at any site that addresses the matter. What you're going through is textbook. If you start to feel bad about what it's doing to you're brother, focus on the things he's said and done to you and consider his complete disregard for your needs and feelings. It's absolute disrespect and it needs to stop.
What my brother did was try to cut me off. He tried to tell me I wasn't good enough for him. This is another method of control. By ignoring you, they're hoping you'll pine for they're attention and reach out to make amends. After two months of not speaking to him, we had a conversation. He owned up to nothing really but now he knows his boundaries. He knows that my mental heath is more important to me than having him in my life.
For the most part, people like this don't change unless they get some serious help. This is unlikely since they've convinced themselves that they're looking out for and so there's nothing wrong with what they're doing. Your best bet maybe to inform the authorities of his "suicide attempt" at the least. Maybe then he'll be forced into counselling.
I wish you the best. Once again, stick to your guns. Don't let him belittle your convictions by saying your too sensitive or any of these other misogynistic creeps here on reddit who doubt you. Everything I mentioned regarding my brother has happened within the last two months so it's all very fresh in my head. Feel free to reach out. We grew up without a father as well (something that I think that has greatly contributed to his behavior) and I feel like were in very similar situations.