Well your first dream you realised after about 10 minutes, at this point your dream may have already been coming to a close since dreams do not last that long. Another point to consider is that if it was your first LD then it may not have lasted long anyway. You can ask anybody on this forum and they will all say that there first LD wasn't anything longer than a few seconds.

First things first, longer lucids come with time and practice but here's something that should help. When you realise, remain calm. Try not to get excited (tricky I know) and don't make any sudden movements. Take in what you can see without moving too much and believe that you will not leave the dream until you have done what you want. Then if you're still in the dream, lower yourself to the ground and feel what is below you. Feel how real it feels, this should instantly stabilize the dream, make everything clearer and lock you into the dream for a bit longer. Once you get to this stage the hard bit is over and you're free to do as you please, just be aware that your time is limited ;P

~DJ