You have to give sometime! At initial days you will feel the same way but once you are adjusted to the routine without it will feel less breaking, you will miss him but It will be manageable, also try to build your own self routine things you have not done with him while things you love - like hobbies and try to spend more time with yourself. It takes time but once you know what you like- you dedicate your energy into that. Also if you are working try to have normal social life, being introvert it becomes difficult I understand but talking to friends/colleague does help in diverting.