There are no magic words to say here, when someone is gone you miss them on many levels, you miss talking to them, you miss them physically, you miss doing things with them, etc. Looking at pictures can be therapeutic and you can talk to the picture. If there is a gravesite to visit, many find it helpful to go and talk to their loved one. Also, I can’t remember if you have siblings but you should be leaning on each other, since we lost my mom just over a year ago, my siblings and I have been spending more time together than usual.
Patty