Minecraft crashing while in survival mode

Every time I'm playing in survival with i crash after about 45 minutes of playing. When i get back on Minecraft i go back to the world and it will only let me play for 5 minutes before crashing again. I have reset the app many times because I thought it was my computer and ive uninstalled the game twice. I'm not sure what to do anymore but its been happening since the new update.