I agree with what WabiSabi is conveying... Contemplation of our inevitable physical 'death' is important and valuable... Eventually you will come to the awareness and realization that you exist independent of your physical body. The fear/concern/worry that you are experiencing is rooted in the influence of the physical/egoic mind (which stems from your physical body)... There is a deeper/higher aspect of you which is not threatened by the notion or experience of physical death - the key is to uncover that aspect and increasingly connect with it...
GotSpirits - since you say that thoughts on this matter are already on your mind, how would you feel about reading about this subject matter so that you can promote a deeper understanding of this very natural and normal life experience? I would firstly recommend books in the Thanatology field (includes descriptions Near-Death Experiences)... Many individuals who have had NDE's report that afterwards they have shed all fear of physical 'death'... I would imagine there are also books written directly with the intent of helping individuals to reconcile and transcend the fear of 'death'... Respectfully, I don't think you can force these thoughts out of your conscious mind or hide from them. What you need to do is develop an expanded/elevated state of Awareness and then the former anxiety-inducing thoughts will become reconciled and resolved....
Welcome to the forum by the way... Glad to hear that you decided to sign up here and discuss this important matter.
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WOLF