Firstly can I just say how incredibly sad I feel for you 
15 years ago I was in your shoes. Although I was a couple of years older than you, my DH was also killed in an accident.
At the time it totally floored me. I felt I had lost my closest friend, our shared past and all the exiting plans we had for the future. I really didn’t see the point of carrying on and had many dark nights just wishing I was no longer here.
After the early intense weeks of grief, I realised I had no choice. My DD needed me, I had a house that was half built, a mortgage to pay and a job that I could not afford to lose.
For most of the first few years my grief and the practicalities of daily life consumed me. However over time, the grief started to soften a little and I began to feel more confident in my own shoes.
Early in my loss I was advised to be kind to myself and I followed that mantra. When things felt tough, I treated myself, perhaps just to a bunch of flowers, chocolate, a good film, or a nice supper. When my family or friends were sad I listened, hugged and tried to make them feel as loved as possible. In doing so, of course I was hugged back.
Grief is not a straight line process. It surrounds you like a mist and at times will be more intense and at other times softer. Over time you learn to to lean into and absorb the softer times, and to save your emotional strength for the more intense periods.
15 years on, I have a very different life, but am extremely happy. My DD now has children of her own, I have moved twice, once half way across the country (scary on your own), achieved a great deal more in my career and have a good social life. I have never remarried, although I did once consider it. I travel with girlfriends or a male friend who is in a similar position and feel I am extremely fortunate to be surrounded by so many kind and supportive family members and friends.
I do miss my DH. There is never a day when I don’t think about him, but my grief is much softer now and I know he would be extremely proud of the way I picked up the pieces and carried on. I always feel that I am living for him, but in the process have found happiness in ways I never expected.
You may not feel it now, but things will eventually be calmer and easier to cope with. Right now, just focus on coping with things one step at a time and make sure you reach out and ask for help whenever you need it.