Confused and Upset
First let me address your mother's reaction to your seeing spirits. That's not an uncommon belief amongst some Christians, but it is not supported by the Bible!
From 1 Corinthians 12:
There are different kinds of gifts, but the same Spirit. There are different kinds of service, but the same Lord. There are different kinds of working, but the same God works all of them in all men.
Now to each one the manifestation of the Spirit is given for the common good. To one there is given through the Spirit the message of wisdom, to another the message of knowledge by means of the same Spirit, to another faith by the same Spirit, to another gifts of healing by that one Spirit, to another miraculous powers, to another prophecy, to another distinguishing between spirits, to another speaking in different kinds of tongues, and to still another the interpretation of tongues. All these are the work of one and the same Spirit, and he gives them to each one, just as he determines.
Clearly, what you have experienced is okay with Saint Paul. I think he's a greater authority than your mom (or mine, who had the same reaction initially), or me for that matter. Simple logic says that a loving God would not give you this ability, which is hard to control for the best of us, then condemn you to eternal damnation for things you can't help! It's not your fault, or even hers, that your mother is afraid. For generations, people have been selectively reading the Bible to support their own prejudices. This is one area where they have absolutely no justification for it. Saint Paul is absolutely adamant - what is happening with you is an outgrowth of the Holy Spirit. It is a blessing, not a curse.
It can be a mixed blessing though. I have also asked why am I given this knowledge if I don't know who this will happen to or when, or even how to prevent such things, many times. I don't have a satisfactory answer, and I've been studying for over twenty years. I have come to terms with that however. That is just the way it is. I don't know what God's greater plan might be. I try to help when I can, but when it is not possible or practical for me to make use of it, I simply make a note of it in my journal, or here in the blog. Maybe each individual moment of insight is not the important thing. Maybe it is more generally how I let my intuition guide me. I don't get attached to finding meaning in each case so much anymore. I do what I can, and take pleasure in that. Otherwise I just accept that there are things I can't know. I don't beat on myself or feel guilty when I can't use it to help others. Sometimes they don't want this kind of help. Sometimes it is risky to speak out. Sometimes I am not sure of my own insights. I feel my responsibility is to develop this gift to the best of my ability and to share what I know where it is welcome. Aside from that, I don't know what it is for. I figure one day it will make more sense to us all.
I think you are scared of spirits because of what your mother said, and not because they are inherently scary things. They are simply people without bodies. People are mostly good. So are spirits. Yes, now and then you will stumble across a frightened, confused, or even very rarely, a negative spirit. But they can't really harm you, can they? Other than being frightened, have you been harmed in any way? And you have control over that. You can decide to accept what is happening to you. When you do, you will find that the experience gets more and more positive. It's funny how that works, but fear is your enemy, it is not your friend. Once you get that, your life will change for the better in ways you can't begin to comprehend. For example, I still occasionally have migraines, but they are far less frequent than when I was in "flight/fight" mode.
I do recommend you get the book or the eBook and study the meditations and visualizations in it. I do daily morning and evening meditations. You can find other meditations online. Your local Buddhist temple or new age shop may offer a meditation class - almost any kind of meditation will be helpful to you. Just sitting by the river may help calm your mind. I also keep a journal of my insights.