Here are a few ideas.
It is almost the holiday season...
What are you good at?
What are you passionate about?
Figure out what those skills are; and write them down, and then think about how they could apply to helping a charity for the next 7 weeks.
Quit the job. Help a Zen Center, a Buddhism Center, your church if you have one, or a soup kitchen, or a homeless shelter, or a battered women's shelter, a prevent child abuse hotline, something that resonates with you and makes you feel good.
As for talking in groups of people. There are 3 kinds of people who want or have to talk in front of other groups of people.
1. People who want to and are naturals at it. (Not all of these people are healthy do-gooders btw, some are sociopaths, or attention whores, and just have the natural talent.
2. People that are Afraid of Public Speaking, and will never fully get over that fear.
3. People who start out with a fear or reluctance to speak in front of groups of people, but who learn how to do it slowly over bits and pieces of their life where it is required, some people learn it in Law School!
Here is a thing people have done to learn how to speak in public -- I once knew people who would go to AA, and claim they were an alcoholic, or frame whatever drinking they did as alcoholism, so they could be in a regular situation where they were speaking in public, daily, weekly. Some started by just going and listening and watching others...and maybe 6 months down the line they spoke for the first time. Over time, they became comfortable and used that experience to transfer into speaking, say, at work.
You can also read a book on public speaking (Dale Carnegie has one) and learn how to conceive a 30 minute talk, and then practice giving it in your place, alone, with an imaginary audience. Once you've done that for a while, you will know your material, and it will be familier speaking out loud to an imaginary audience, and as it turns out knowing your material is 80% of the battle, when you are confident in your "talk," well you aren't straining to remember anything, or perform, and the nerves go away.
I've also known people who took sales jobs that they knew they would hate, would not stay in, simply for the training and repitition they would get at talking to people, asking questions, describing goods or services, and "selling." (No one sells anyone, they sell themselves based on what they have heard from you, do a good job and they almost always ask for the sale before you have to, so it is kind of ironic that in the best sales...there is no sales.)
I know tons of people that have had sales jobs, maybe did not enjoy them (fear of rejection, performance expectations) but they look back and are GRATEFUL that they braved the experience cos everything they learned helped them in every job they have had since.
Re: Your mother and sister. This is counter intuitive and may seem harsh to some. You do not owe them anything. Are you going to stay loyal to the automatic behaviors of a family system and your childhood all your life -- or are you going to pursue that vision of finding the place and the thing that is fulfilling to you?
There is always the phone, skype, and airplanes a few times a year.
Find what inspires you and do it. Anything less will be a noose with a weight attached to it around your neck for life. If you let spoken or unspoken family pressures or influence prevent you from doing what you want, what fulfills you...you will die with an unfulfilled life and probably reach real unhappiness at some point.
I don't know a single happy person who does something they don't enjoy.