I'm feeling depressed, anxiety, and low self esteem

It sounds like you are going through a lot.  A lot of times we spend all our energy trying to help others and reach a place of burn out.   We become emotionally drained and are not taking the actions in our own lives to take care of ourselves.   Our self care suffers over time as we do not maintain our own physical, spiritual, and emotional well being.   As anxiety and depression grows, we lose sight of our own goals and what we want to accomplish in life. 

The first thing I would recommend is better boundaries with others.  Boundaries are very tough for a lot of people, especially when we have lower self esteem.  You can think of boundaries as this.   We all have things we are comfortable in doing, having others do to us, and are comfortable being around.  These are the things that live outside of our boundary lines.  In these cases, we do not have to assert our boundaries because we are fine with what is going on.  However, we also have things in our lives that we are not comfortable with, we are not comfortable doing for others, or we are not comfortable being around.  These things lie within our boundaries.  When we are most healthy, we assert our boundaries with others meaning that if someone asks us to do something or be around something we are not comfortable in doing or feel is not in our best interest in doing, we assert that we are not comfortable with what they are asking of us.  We, in a sense, say "no" to anything that lies within these lines.  When we assert our boundaries, we feel better about ourselves and maintain healthier relationships with others.   However, when we do not assert ourselves and become passive, we let others cross our boundaries.  The end result is that we often begin to resent the person and we feel worse about ourselves.

This may explain why you are not doing well with your siblings.  They may be crossing your boundaries and you may not be asserting your boundaries and maintaining what is healthy for you.  This passiveness leads to more anxiety, depression, and lower self esteem.  I would suggest you better establish your boundaries with your siblings and make them less dependent on you.  I always ask the questions "what would they do if I did not help?" and "is what I'm doing the healthiest thing for them and me?"  I always liked the saying if you give a man a fish, then you have to give a fish everyday to him.  But if you teach a man to fish, then he doesn't need a fish from you everyday. 

Anxiety is a common, yet distressing emotion when it is at very high levels.   Anxiety leads often to avoidance behaviors where I avoid the anxiety causing situation which causes temporary relief from the anxiety, but causes the anxiety to increase over time.  Anxiety becomes better when we simultaneously stop the avoidance behaviors and begin to learn and utilize coping mechanisms to address the anxiety. 

Coping mechanisms for many people can be learning and utilizing grounding techniques, mindfulness exercises, distraction techniques, exercise, having structure, and finding enjoyable hobbies and other activities.   A common grounding technique is 5-4-3-2-1.  In this exercise, I look around and find 5 things that I can see, then I close my eyes and notice 4 things I can touch, 3 things that I can hear, 2 things that I can smell, and 1 thing that I can taste.  There are many more grounding techniques, but all of the take the focus off of what I am thinking and put my focus on my 5 other senses.  You can think of any negative emotion such as anxiety and depression as a product of my thinking patterns and non adaptive behaviors.  if I think in anxious or negative ways, I will likely feel negative emotions. 

As we cannot feel our way into thinking, we have to think and behave our way into feeling different.   Learn to be more self aware of your thoughts.  When you notice negative self talk, learn to challenge these thoughts by looking at their validity.  You can also learn to replace a negative thought with a more positive one.  Some people find it helpful to journal their thoughts.  Journaling thoughts and emotions can also be a way of processing them. 

Therapy can help you learn how to deal with negative thinking and actions leading to more positive emotions.  In therapy, we can often find patterns in our thinking that lead to negative emotions.  Cognitive distortions are ways of thinking that increase anxiety and depression.  We often focus on the negative, personalize things, overgeneralize, or think in extremes.  We also often put many expectations on ourselves and others, leading to frequent disappointment in life and sometimes the feeling of losing hope.  It is helpful to try to eliminate "should" statements in our lives that put numerous expectations on us and others.  A writer once said that he had found out in life that the level of serenity he was able to experience was directly proportionate to the level of expectations he placed onto others.  When he stopped putting so many expectations on himself, people, and things, he found life much more peaceful and enjoyable.  We are also a product of our pasts and many people have unaddressed trauma that effects them in the present.  Our past determines in many ways how we think and why we feel certain ways.  Therapy helps us to better explore our pasts so we can be free of the harmful effects of it. 

Our actions are very important in having change in our lives.  I encourage you to be kind and forgiving to yourself.  Learn to take better care of you.  Seek help through therapy when you need it.  Learn to love yourself.