Brother, it is not about 'when' the end is coming.. even if it were 1000 years away, it matters not.
For a moment, put yourself in the shoes of the 1st Century Christians... how far away were they from the end? They never saw it, but regardless, they focused on their faith, and were "in expectation"... this is not to say they were obsessing over a date or time, or how long it would be, but they were wary of their "heart conditions", their dedication to Christ, and his teachings, and worship of the Father Jehovah. Because they knew they would be judged "in the end".
Remember the Proverb "delayed expectation makes the heart sick".
This is what you (and many) are experiencing, because your focus has become "a means to an end". That "if I preach just a little longer, if I keep attending meetings... Armageddon will come tomorrow! And I won't have to wait any longer!".
But expecting the 'end' to come tomorrow as a "basis" for "endurance" is not a good path.
We all want the New Kingdom to come to this Earth, but, when it does, it will be for the righteous, those who are dedicated into putting on the new personality. Being a Christian is not merely defined by preaching the Gospel. It's a big part of it, but it's "living it", in your heart, in the way you treat people, the love you share, and feel. It's a way of life.
Therefore, in your life as a Christian, let it be for the glory of our God and Father, and of his Son.
"Therefore, whether you are eating or drinking or doing anything else, do all things for God’s glory " - 1 Corinthians 10:31
We will be judged in the end, whether it be at the coming of Christ, or in the resurrection, for the things we have done and will do. Thus, the message is this, "be baptised and believe on the Lord Jesus and you will be saved" (Acts 2:38, Acts 16:31).
It's following his command, his teaching... not waiting on a date. That will come of its own accord, in the meantime, simply "be".
There is no train to miss. Our victory and relief is not ensured by being alive during the time of his arrival, but by "being alive in spirit", living in accordance to Jehovah's will. Relax, and know our Lord Jesus comes when he comes, be it now, in 20 years, or 100 years. The end will come, we don't know when, but it's the promise of God which is our true endurance, that all who obey him and his Son, will inherit everlasting life, in one way or another.
Live for God, because it is the "right thing to do", not because of expectation of the imminent end, or you will burn out quickly, it's a poor "foundation", which the "fires" of this world will burn to the ground, but the true foundation, our hope in Christ, our life of righteousness, and hope in the resurrection, and the Kingdom that will come, be it the next day from now, or far in the future, that is the "true foundation", which endures fire.
"For no one can lay any other foundation than what is laid, which is Jesus Christ.+ 12 Now if anyone builds on the foundation gold, silver, precious stones, wood, hay, or straw, 13 each one’s work will be shown for what it is,* for the day will show it up, because it will be revealed by means of fire,+ and the fire itself will prove what sort of work each one has built". - 1 Corinthians 3:11-13
"Who of you by being anxious can add a cubit to his life span? 26 If, therefore, you cannot do such a small thing, why be anxious about the remaining things?+ 27 Consider how the lilies grow: They neither toil nor spin; but I tell you that not even Solʹo·mon in all his glory was arrayed as one of these.+ 28 Now if this is how God clothes the vegetation in the field that today exists and tomorrow is cast into an oven, how much more will he clothe you, you with little faith! 29 So stop seeking what you will eat and what you will drink, and stop being in anxious suspense;+ 30 for all these are the things the nations of the world are eagerly pursuing, but your Father knows you need these things.+ 31 Instead, keep seeking his Kingdom, and these things will be added to you" - Luke 12:25-31
"You are going to hear of wars and reports of wars. See that you are not alarmed, for these things must take place, but the end is not yet... Concerning that day and hour nobody knows,+ neither the angels of the heavens nor the Son, but only the Father". - Matthew 24:6, 36