As Alycia said, you are not alone, we feel your ‘pain.’ I’ve come to except that as long as I am in this world, maintaining the momentum in my spiritual life will always be a a struggle and process. As Paul said, "And we all, with unveiled face, beholding the glory of the Lord, are being transformed into the same image from one degree of glory to another. (2 Corinthians 3:18 ESV) This life is a transformative process.
For me personally, I have found that engagement is what keeps the momentum of my spiritual life moving onward and upward. When I’m engaging people of other worldviews on a daily basis, entering into spiritual conversations, asking questions that put the “pebble in the shoe” of a person so the Holy Spirit can begin working in their lives, etc., the engagement acts as a catalyst in helping to keep me in the “spiritual zone” so to speak. These conversations create a desperation that causes me to dive more deeply into the Word for answers to the questions that others are asking so I’ll be better prepared to help my non-believing friends and those I meet to take one step closer to Jesus Christ. One of the mottos that Stand to Reason (str.org) has is: “Be reasonable-An Ambassador has informed convictions (not just feelings) gives reasons, asks questions, seeks answers, and will not be stumped by the same challenge twice.” I don’t always succeed in every conversation, but those stumbles drive me back to a deeper dive into His Word so next time, I’ll be better prepared to help the person the Lord has brought across my path.
The verse that I try to implement and live each day is Col. 4:6: “Conduct yourselves in wisdom toward outsiders, making the most of the opportunity. Let your speech always be with grace, as though seasoned with salt, that you may know how to respond to each person.” For me, witnessing/engagement is the key to a robust and vibrant life and relationship with the Lord, as it causes me to draw close to Him in desperation for all I need and lack, and it brings a supernatural fulfillment in knowing that I am doing my part to fulfill the Great Commission He has given us.
One last point, when studying the other day it struck me that Jesus’ first Words in Matthew were, “Follow me and I will make you fishers of men,” (Matt. 4:19) and His last words before ascending to Heaven were, “But you will receive power after that the Holy Ghost is come upon you, and you will be witnesses unto Me…” (Acts 1:8) I found that to be a nice pair of 'bookends."
I hope this is helpful. I will be praying for you.