I am not sure I can say that the poster above me hasn't, but I just want to say you have beautiful hair, and that I think this is about more than your hair. I am throwing good thoughts and vibes your way, and I hope you can come to terms with things (your hair and peole's reactions to it - because it's FANTASTIC!)
I am not sure, though, if it is 4b. You have a very clear curl pattern. I am not a proponent of the curl-typing system, but I said this because you said 4b and when I opened your pics I was surprised by what I saw.
I was mad for you and the people you call friends (and the hairstylist you trust your hair and money to) to be making a joke about your hair is unacceptable, especially considering they know you are sensitive (and even if you weren't, not cool)
Maybe it will help if you look into the tightly curly method. The woman on that site seems to have hair similar to yours and she has managed to make it work and grow, if you are willing to do the work she puts into it.
I wish I could say something more, insightful or exactly what you need, but again my best thoughts go out to you.
ETA: There is a straightening/relaxing forum on this site as well. It might be a helpful source of info if you go that route.