Hi, I'd like to help you with your question.
It sounds like you may have had depression for a while now and it was aggravated by your isolation and feeling that you have no goals in your life.
To start your recovery, take small steps to help yourself each day. I know it feels overwhelming, but even a small effort is going to help you move forward and get through this depression. Start by setting a goal to get out of bed each morning. It is hard to do, but try. Set out clothes and get yourself dressed. Eat breakfast with your children. If you need to, go back to bed afterwards. But if not, stay up. Set a small goal, something you like to do. Then see if you can stay out of bed and complete your goal. Keep doing this until you feel you can stay up all day. Continue to make goals like this and push through the depression.
Think about a goal you would like to achieve in your life. What is something that makes you feel good and that you think you could accomplish? Focus on that goal. The small steps you take now are to reach that goal. Use the goal to motivate yourself each day.
You mentioned feeling isolated. You may not be able to see your family, but making a few friends would help. Again, start slow with your goal. Once you are feeling up to it, go out and try small talk with anyone you meet in the store or other places. Smile if you can. You may not feel like it, but sometimes you need to do something you don't feel yet to make yourself eventually feel it.
Talk with your doctor about your medications. They may not be working for you. It is very common for people to try various medications before finding ones that work. The medications should be at the very least helping you cope with the symptoms of your depression.
Consider talking with a therapist. Medications are great for helping you deal with symptoms, but they do not address the original problem. I am not familiar with they mental health system where you live, but if you talk with your doctor, they may know therapists you can see. The therapist can help you learn how to cope with the depression and help you get to the root of your problem.
Here are some books that can help you as well:
Overcoming Depression One Step at a Time: The New Behavioral Activation Approach to Getting Your Life Back (New Harbinger Self-Help Workbook) by Michael E., Ph.D. Addis and Christopher R. Martell
Self-Coaching: The Powerful Program to Beat Anxiety and Depression, 2nd Edition, Completely Revised and Updated by Joseph J. Luciani
The Cognitive Behavioral Workbook for Depression: A Step-by-step Program (Workbook) by William J. Knaus and Albert Ellis
You can find these on Amazon.com or if you have access to a library, they may be able to get them for you.
I hope this helps you,