What do I do?

Assalamoualaikoum,you can make tauba again and stop doing the sins,if you repent honestly insha allah yu shall b forgiven for Allah is merciful

also ask Allah for strength to overcome your desires. There is a nice du'a

Praise and Glory be to you Oh Allah you are the Most High the Most Merciful

Oh Allah, i beg that you strengthen me and fortify me with faith, patience, love, peace and extinction of my selfish desires

Oh Allah, i beg that you purify my intention and allow your perfect and holy Will to take control of my mind and use it to carry out your perfect intention

i beg that you capture my soul in the light and purify it with a through purification

i sacrifice my identity, my life and my soul to you Oh Allah that you may use me as you Will

i beg that you continue to strengthen me with immeasurable faith, an unbreaking spirit, courage, nobility and patience as i make my way through the darkness and into light, through the fire and into the Kingdom, from ignorance to knowledge and from selfishness to selflessness

As i cross the ever so narrow Sirat, i beg that you strengthen my spirit by granting me eternal light, patience, understanding and knowledge

Oh Allah, if ever i stumble from the straight path, i beg that you strengthen me with the power to achieve so that i may never fall into ignorance, fear and weak faith

i beg that you strengthen me with eternal remembrance

i beg that you strengthen me to always control my emotions in every situation

i beg that you strengthen me to submit to you perfectly

I beg that you strengthen me to never sin again and to be a perfect manifestation of your Will

i beg forgiveness for all my mistakes and all my sins

i beg that you strengthen me to enjoin the right and forbid the wrong

Praise and Glory be to you Oh Allah

Your Will be done

(http://www.religiousforums.com/forum/islam-dir/21880-dua-strength.html)

Asslamo a'lykom, understand those two verses well and insha Allah you will have fear from repeating the sin. Allah says in surat al Nisa' verse 17 & 18. "[The repentance accepted by Allahis only for those who do wrong in ignorance [or carelessness] and then repent soon after. It is those to whom Allah will turn in forgiveness, and Allah is ever Knowing and Wise.][But repentance is not [accepted] of those who [continue to] do evil deeds up until, when death comes to one of them, he says,"Indeed, I have repented now," or of those who die while they are disbelievers. For them We have prepared a painful punishment.]" may Allah bless you. Allah knows best