What is the way to persevere in prayer and repentance, and how can I be with God?

Your feeling of guilt is an indication that your heart is alive, and its goodness is perfected by working diligently to change and reform yourself. Be truthful with your Lord, for Allah takes care of the truthful, and "As for those who strive hard in Our cause, We shall most certainly guide them to Our paths." Striving against one's self is among the best forms of striving, and whoever adheres to obedience to Allah will be guided to more of it. Guard Allah's commands, and He will guard you from yourself and its desires, and from Satan. Remember the danger of abandoning prayer, for it is a grave sin. Adhere to the remembrance of Allah, strive in supplication, and associate with righteous women, for "A person is on the religion of his intimate friend."