Hi Jenn,
I'm also 44 and was 41 when I was diagnosed with cancer in my lower right jaw. I had a major surgery and radiation treatment and am cancer free today. I have 7 beautiful daughters and three grandaughters and I can certainly relate to how you feel when you think of your daughter. I would look at my youngest, who was 9 at my diagnosis, and realize that if I did die from this cancer then I had the easy job while the tough one was up to her, she had to go on without me and that is a tough thing. Please don't ignore the feelings you have, they are normal, very normal. BUT you also have to learn how to look at life in a new way, your life as you knew it is over and you are about to begin the process of saying "goodbye" to your former self. It's hard and it's long but it does happen. I think of my life in two stages now, before cancer and after cancer. While my life now is full and wonderful, I still get a homesick feeling now and again for my old life, the one where I still had that global safety net under me and thought of end of life as being well into my 80's. I may still live well into my 80's, but I don't EXPECT it now like I did before.
My advice to you is to allow yourself your sad feelings, let yourself cry, but limit it to an amount of time that won't affect your day to day life. I had reached the point after radiation that I couldn't be in the same room as my youngest without crying, which had a negative effect on her. I had allowed the cancer to define me and to consume me. Avoid that if you possibly can. We all need to wallow in self pity for a short time, but then we snap out of it and fight like hell to say alive. Take walks, talk to people close to you about how you feel, keep yourself busy.
Wishing you well.
Minnie