I keep thinking that my mom is going to come back, that when the phone ringing it is her calling, that at any point she’s going to walk in the front door. How can I convince myself that she is gone?
This is normal. Our minds can create situations that we know are not real. It is not uncommon to see someone walking down the street who has some resemblance to your lost parent and think that it is him or her. These are all ways of remembering the person and trying to help work through what happened.
Finding yourself wearing some of your parent’s clothes, or acting like the lost parent, or doing similar things, can be coping mechanisms to deal with your loss. This is often done without consciousness. Whether it is dressing like them, or having interests like them, may be an important part of your healing process. It gives you a way to integrate your loss and make the person part of you.
Yet, if you are doing these things, then they are a subtle indicator that your parent is gone. What you have left is the memory of your parent, which incites you to wear your mom's blouse, or your dad's tennis shoes. Realizing the cause behind these actions will help you realize that your parent is gone.
There is no "absolute" way to convince yourself that your parent is gone, though. This can be a very individual thing to you. However, you can rest assured that it is very probable that with time, you will come to recognize this fact. Due to this, you may not need to "convince" yourself that your mom is gone, as time will gradually steer you to that conclusion.