assalaamu 'alaikum wa rahmatullaahi wa barakaatuh,
Please see this article on sincere repentace by Shaykh ibn Baaz - rahimahullaah: English Arabic (Shorter: English, Arabic).
Also, below is a list of (Arabic) Audio's on Dhul-Hijjah by different scholars. The first list is about the 10 days, the second is about the Udhiyyah & the third is about the 'Eed.
فضائل العشر من ذي الحجة – أحكام الأضحية – آداب العيد (لمجموعة من أهل العلم)
May Allaah help us correct our hearts and carry out the acts of worship in a way He is pleased with and then accept it from us.
The pieces of advice offered by al-'Allamah ash-Shaykh ibn Baaz & Shaykh 'Uthaymeen - may Allaah have mercy upon them both - can be found in #1 to #3.