Hi, I have another problem, I did the quest Rising at Dawn to get cured of my vampirism but it didint work, I still am weak in sun and stamina is weak , I looked in active effects and all the weakness that the vampire lord had is still there, but when I speak to serana I have an option to ask her to make me a vampire,is this a bug or what ?, the quest is supposed to cure you but somehow it didnt work, does anyone have any advise or ideas on how to fix this?

If you can keep re-doing the quest, try becoming a vampire again and re-curing it. See if that helps.

Try reloading from an earlier save, assuming that'd still be a viable option for you in this instance.