How can I deal with the stress of my mother?

This sounds like a pretty difficult dynamic and I am sorry to hear how it is impacting you.

I would encourage you to try and observe the relationship from an outside perspective to begin with.  Try to see what it is that causes your mom to be upset (such as you responding in a tone of voice she doesn't like) and see if there is something you could change on your end.  If you are able to change something, like your tone of voice, start there.  You could also try asking what you could do to help, perhaps she is frustrated that the trash wasn't taken out.  You could also sit down and try to hash things out with her, if you feel like that could be beneficial.

Ultimately, you are only in charge of you.  The things you say, your behaviors, are all controlled by you.  So it is important to recognize that no matter what, you can't control what she says or does.  Obviously the things we say or do can impact others, which is why you are frustrated over her behavior.  But remember that you are able to only control yourself.  

Seeking therapeutic intervention could also be beneficial for you, and even having her join in to help.  I hope you are able to figure something out and I wish you well.

This is a common issue. You grow up gradually, and parents often forget to shift their habitual responses according to your newfound level of maturity and growing need for freedom and independance. I'm all for helping you find new ways to cope and interact with your mom. 

Ultimately, you only have control over yourself, so that's the place to start. You can remind yourself that Mom's behaviours don't mean that she doesn't trust you or love you; it's just that she has habitual ways of talking to you that seem stuck in the fourteen year old range. If you can see her responses as habits, rather than a reflection of how she feels about you, then you can keep yourself calm. The more calm you are, the more she will buy into it when you invite her into a different sort of relationship. 

Take a look at the picture from her perspective. She may feel overwhelmed with finances (are you in college?), and feel burdened by the mundane tasks in life that she doesn't know how to recruit help for. I bet your mom spends a lot of time picking up after you, cleaning, cooking, doing laundry...all those thankless mom tasks. Take a look at how she talks to you... is she nagging about chores? Can you see that underneath the nagging there's a pretty overwhelmed and powerless person who needs assistance?  Okay, so my guess is that you both have a legitimate beef. She wants help. You want respect. Let's talk about how you get both.

I propose that you sit down with mom and negotiate out a different sort of dynamic. "Mom...I see us as stuck in how we interacted when I was fourteen. Can we do this differently in a way that we both get what we want?" Sell it as "win-win". Then you write down some things that end up forming a contract. 

The first part is stuff that's your business and your business alone: things you want your mom to respect, like your room, your school, your job, your personal relationships and hygiene.... Mom's voice has no place in these arenas, unless you are storing food in your room and it's a health hazard. This is a "Mom says nothing about" list. 

The second part is about what Mom needs from you. What are her expectations about your role in the home as an adult. Does she want you to contribute to rent? Buy your own food? Do your own laundry? What items can we put in your control that would take some burden off of Mom? How will these things be enforced? What will happen if you don't follow through? Write it all down so it's really clear. It has to all be mutually agreed upon.

The third part of the conversation is about how she talks to you, and how you talk to her. You can let her know that you don't want to be told what to do or when to do it; that doesn't work when you're 20 years old. Listen to what she wants too. Beyond the contract you've just written up, anything else you want from each other is a request, it's optional, and whether and when you do it is at your discretion. My guess is that if she spoke to you with more respect, you'd be more willing to help out. AND, I think if you participated a bit more she would nag at you less. Go for the win-win. 

I wish you well as you negotiate a new relationship with Mom. :)