They say 'time is a great healer' - but they always neglect to say how much time that might be!
It's different for everyone, but it doesn't work in a linear fashion -it's not a train on a track, and each day you are further away from the pain than ytou were yesterday.
Rather, it's like a small boat on the ocean, some days you pooter along in bright sunshine, making progress, then a massive storm appears and blows you further back than where you started.
Be good to yourself - enjoy the things you like to do with friends, or by yourself, and don;t get hung up in the need to replace him - you don't 'need' to, and you won't anyway.
What will happen is that this experience will weave its way into the fabric of your life, and eventually it will be an experience that has made you the person you have become, but it will take time, and there are no short cuts.
Be patient, and ignore time going by, it's not a race, no-one is waiting with a gold medal because you 'got over' him in double quick time.
So be aware that this is a work in progress, and don't make any rash decisions about anything - just be gentle with yourself, and you will get past this - promise x