When to assume Ihram for Hajj Tamattu`

Q: Allah (Exalted be He) has graced me with performing my obligatory Hajj this year along with my husband's parents even though my husband could not accompany us because of the circumstances of his work in the Kingdom of Saudi Arabia. Any way, I stayed in Makkah for one full month during which I performed `Umrah (lesser pilgrimage) and intended to perform Tamattu` Hajj (combining Hajj and `Umrah with a break in between). The point is that we entered Ihram (ritual state for Hajj and `Umrah) on the seventh of Dhul-Hijjah then we headed directly to `Arafah where we stayed the seventh, eighth, and ninth of Dhul-Hijjah. Is this valid? What is the ruling if the answer is in the negative? Moreover, myself and my daughter got lost while we were walking from `Arafah to Muzdalifah. We went far away from our group (Part No. 11; Page No. 203) but Allah, all praise is due to Him Alone, facilitated the matter for me via the help of an Egyptian man and his wife whom I accompanied until we returned to Makkah to make Tawaf-ul-Wada` (circumambulation of the Ka`bah on leaving Makkah). They even took me to Jeddah where I could go to my husband's parents and my other child who was with them. Due to the circumstances mentioned above, I intended to combine Tawaf-ul-Ifadah (final obligatory circumambulation of the Ka`bah in Hajj) and Tawaf-ul-Wada`. The driver gave us a two hour time limit to finish Tawaf before we could return to Jeddah. The sister told me that it is permissible to perform Sa`y (going between Safa and Marwah) before Tawaf because Tawaf should be the last thing a pilgrim does before leaving Al-Bayt (the House: another name for the Ka`bah). I followed her advice and performed Sa`y and Tawaf quickly lest I should be late as they were waiting for me, and my daughter was with them. After I returned home I read that amongst the conditions of the validity of Sa`y is that it should be preceded with Tawaf.Is it permissible to perform Sa`y before Tawaf-ul-Wada`? What is the ruling if what I have done is invalid? If it is obligatory on me to offer a sacrifice, can I ask someone in Makkah to do this on my behalf bearing in mind that it is impossible for me to go to Makkah now and may be until I return to Egypt?