I'm so sorry, Jen. Losing your mum at any age is hard, but it is even harder when you were both still so young. Life is cruel and all you can do is be grateful for the time you did have together and try to accept that you cannot change what has happened, much as you would like to.
I think part of the problem of losing someone when they still should have had years left is that we are grieving not just for them, but for a future you have not known and have lost all the same. You feel this shouldn't have happened, that neither they nor you deserved it and that is painful in itself. For me, it was the other way round. My mum had a very serious heart problem when she was pregnant with me and in those days, that meant a very new and risky operation to try to save her. Neither of us was expected to survive, but we both did and so now, although even at the ripe old age of 96, I still did not feel ready to lose her, I know we both have had years that were a gift because neither of us were expected to live all those years ago. So, I know we did our best to make our days fun and as happy as possible, even when times were hard. We have never been rich! But now, I still feel an obligation to make my life as good and as much fun as it can be, because I might very easily never have lived at all! I suppose what I am trying to say, Jen, is that life, not just grief, is a rollercoaster and a risky ride and we have to just go with the ups and downs and accept the journey we are taken on and make the most of it whenever we can. We are not always in charge of the route or the choices, so have to live with them and have an obligation to make the best of things and make the time we have as good as it can be.
You lost your mum and that is one of the hardest things to bear, but she is still in your heart and your memories and it sounds as if she worked hard to make those memories with you, so treasure them and be happy when you think of the time you spent together. She will never really be gone from you, because you will never forget her. But it is up to you now to make her proud and live as good and happy a life as you can without her. We are all forced to accept that everything has changed once our mum dies, and adjusting to this new existence is very difficult, but once acceptance comes, you just have to get on with it and make it as good as it can be, so that when you do see her again, you have plenty to tell her about!
I know how much pain you are in and you probably feel some anger too, Jen, but one day at a time. It will get better. You had her love and that is your treasure still. She would want the best for you, so you have to create that best for yourself now and she is the basis and foundation for that new future. We can't change the past, but the future is up to us. Your life is her gift to you, so make the most of it, for both of you.
Sending you strength and an understanding hug, Jen..xx