Smee,
new year has begun, you have a lot of things that you will have to do. Moving into new area can be stressful, make you anxious and worried. I know its hard to get to a new place cos you spent so many years in your house and maybe fear of unknow makes you feel depressed. But this will for sure bring something new, new people in your live, new neighbors. You were fighting for that, mostly cos of your kids. Remember, your kids will always need you, no matter how old they are/will be. They love you so much, want to live with you, feeling comfortable staying with you. Its normal that they are growing up, you cannot stop that, but they are your kids. Growing up they will need you more and more. They will come to you with their problems, you will be their support in their life. They need friends which is normal, but doesn't mean that they need you less.
Your youngest son is special little guy who loves you the most. He will always needs your attention, more then two others.
And you cannot know what is behind the corners, you cannot know what time with brings, but you have to be here cos they need you. Leaving house very rarely is depressing, but maybe you are so get used on that that you are scared to change it. Try to get more out, even alone, you need to be among people, you have friends, call them, don't wait that they call you.
Be pleased with your life, you managed on your own for so many years, which means that you are strong person, you have wonderful raised kids thanks to you. Lead them through life, they are still kids, and they make your life better and full.
Try to force yourself to get out, at least few times a week, you will see how you will feel. It will be hard on the beginning but don't look for excuses not to do that. Keep moving on, maybe to find a hobby, some clubs that you will meet your interests, where you will meet new people.
Talk to your psychiatrist, maybe he can suggest something to do.
You know that you are strong person, you went through a lot in your life, so keep fighting for yourself, your kids and people who loves you. We love you, need you here. Need you around and want to see how you started to change your life in a good positive way.
HUGS