How can a person who has committed sins after intending to start a perfect beginning with God, and is determined to repent but does not feel remorse, repent and attain acceptance and blessings from God?

What you have done by delaying repentance and committing sins is a mistake that necessitates repentance. Regret is the heart's pain over sins, and your desire to repent may be an indication of your remorse. You must sincerely return to Allah with a general repentance that includes all your sins, resolving not to return to disobedience and regretting your shortcomings. Accompany the righteous and build an environment of faith that helps you in obedience, and adhere to dhikr (remembrance of Allah) and du'a (supplication). Strive against yourself to do good deeds and abandon evil deeds; for Allah helps those who strive, as stated in the verse: "And those who strive in Our cause — We will surely guide them to Our paths."