I pray to Allah to accept your hajj and make it a virtuous one.
We read in an authentic tradition on the authority of Abd Allah b. Abbas: The Prophet (peace be upon him) appointed dhul hulayfath as the meeqaat for people of Madinah, for the people of Syria al-juhfah, people of Najd qar al-Manaazil, and for the people of Yaman: yalalmlam. He further said, "These are the meeqaat for them as well for those who proceed to Makkah through those routes-if they intend to perform hajj or 'umrah. However, as for those who reside within the meeqaat, let them assume ihraam from their place of residence; thus, the people of Makkah should do so from Makkah." (Reported by Bukhari and Muslim).
Based on the above tradition you should assume ihram from Jeddah. Hence even as you assumed ihraam for 'umrah of tamattu' from Jeddah, you should assume ihraam for hajj from Jeddah as well, unless you stayed in Makkah after having performed 'umrah until the day of tarwiyah (i.e.8th of dhul hijjah), in which case, you should so from Makkah itself.