Hard sometimes

This semester is turning out to be a bit harder than I thought it would. This is mostly because the majority of my professors treat me like I am an imbecile.
Seriously.
Today, after presenting (an admittedly not so great) topic for discussion, my professor pissed me off so much that I am still a little peeved. I will have to start from the beginning...

We read the first two books of George Elliot's Mill on the Floss, and my job was to present an observed detail to discuss. I chose to talk about Tom's attitude. Whether or not his desire to punish is an actual sense of justice or if it is simply based on his self-righteousness. While the two are not exclusively separate (and I think this part of the conversation was the most confusing...) I simply wanted to discus whether or not the reader is supposed to perceive Tom as being in the right. And, if we are not, is it correct to call how he acts just? I thought it would suffice for the detail aspect of the conversation, but it did not. The conversation ended after the professor interrupted me twice to say that the narrator says he has a concept of justice. (I obviously knew this, but it was not my point) I realize that it was a faulty topic, but no need to be rude. Anyway, I did have more of a point than just that.
I wanted to talk about the Dodson family. More importantly, the aspects of the Dodson family that Tom portrays in these first few chapters. The first book is basically all about the Dodson family values. Or at least what they represent.
So, in response to the second part of my discussion question he said, "Well, you actually did talk about something relevant." And if he could have just sounded a little less surprised, I may not have gotten all grumpy about it...
Ok. It may not be all that big of a deal, but if there is just one thing that I can't stand, it is to be made to feel stupid. Inadequate. And that is how I feel.
I know I am not the smartest person. I am not the smartest even in that class. I am not an honors student. And my GPA is not the best. But I don't like to be talked down to. I don't like to feel a lack of respect. And just because I do not have a PhD or Masters degree does not mean that I am lacking.
It is not only him. A lot of my professors or TAs treat me in exactly the same way.
It's frustrating to think that I am not good enough.
I need to put less stock in how other people act toward me.