Your prayer has touched upon the very matter which most concerns every soul, for the fear of death is natural to man as a sinner. That fear, as you have felt it, answers a good purpose when it drives us to seek mercy, and in that sense it is a wise and beneficent arrangement, for it has often been made to subserve the highest purpose of Divine Mercy in leading sinners to consider their latter end.
Yet while the fear of death is natural to the sinner, it is not necessary to the saint. This sorrow of the flesh ought to be avoided, and we ought to seek for Divine Grace to conquer it, for to remain in bondage to it is dishonoring to God. The question then is, where shall we look to be delivered from the fear of death.
Scripture answers, looking unto Jesus. He is He who conquers for us the fear of death. Through death He destroyed him that had the power of death, that He might deliver them who through fear of death were all their lifetime subject to bondage. Let your eyes be always looking to Him, then the fear of death will not hold you in bondage.
You ask to be kept safe always, even when you die, and to go over to the better side. Know this, that safety is not found in a vague hope, but in a prepared state. Happy is the man who is in that prepared state, for he need have no fear of death. That prepared state is to be in Christ, trusting in Him alone for salvation, for there is no other name under heaven by which we must be saved, and no other intercessor or mediator. The saints in Heaven sing of Him alone, Thou art worthy, for Thou wast slain, and hast redeemed us. Their Heaven is not merely a better side in some general sense, it is the Heaven of Heaven, that they shall see His face.
To enter fully into that inheritance we have only to cross the narrow stream of death, and scarcely that, for the kingdom of Heaven is on this side of the river as well as on the other. Heaven must be in us before we can be in Heaven. When Christ is in the heart, the hope of glory, when the love of God is shed abroad in the heart by the Holy Spirit, you have got the major part of Heaven already.
Therefore I would urge you to use the telescope very frequently. Look often toward that better land, not with a slavish fear that something evil is about to happen, but with the loving fear of a child who would not grieve so tender a Father, and with a firm trust in the finished work of Christ. As you think of what He did for you, believe in Him, and get your assurance out of Christ Himself. You may come to Heaven with many doubts and fears, but you cannot come there without trusting the Lord Jesus Christ.
May the Lord grant you grace to rest your soul upon that rock without fear, so that living and dying you are kept safe in His hands, and when He calls you hence, you may find that to depart is to be with Christ, which is far better, and to see His face forever.