Assalamu alaykum sister,
MashaAllah, welcome to Islam and TTI.Allah has guided you sister to this faith of submission to His will.Well sister now that you are a Muslim,when you reverted to Islam you were as sinless as pure as a new born baby Allah forgave all your past sins the.Alhamdulillah!If you sin after that then the best thing to do is repent...Taubah...ask forgiveness from Allah for He is oft -forgiving Most Merciful and expect his mercy for Allah says in the Qur'an::
“Say, ‘O My servants, who have transgressed against their souls! Despair not of the Mercy of Allah: for Allah forgives
all sins, for He is Oft-Forgiving, Most-Merciful.’” (39:53)
So do not despair sister.
Secondly yeah I know habits die hard but certain habits can be changed like for example I've heared that Hazrat 'Umar Farooq (May Allah be pleased with him) had a habit of anger he changed it into anger for kufr and haram things so habits can be controlled you see they arise from Nafs.Seek refuge in Allah from the evil of everything and abstain from following the vain desires be it yours or others.Thats the best .Besides that keep a company of good Muslims around you,mashaAllah as you are here now inshaAllah you will get it

,besides that 'Unoccupied mind is devil's workshop' so try to keep yourself busy either in the deen of Allah or the wordly things necessary regular stuff.Dhikr is the best way to repel evil thoughts,so it will be quite helpful as well.In the days of my Jahiliyah I used to suffered from such things as well;I asked my cousin who used to be a contrast to a good Muslimah :astag: but now Alhamdulillah

she is what you can call a good Muslimah 'How did you leave all those things baji?'
She told me that 'Just like when you are fasting you abstain from food and drink,likewise think of this life as a fast and abstain from evil and ractise that which is good.'
So this really had an amazing effect on me and am sure inshaAllah you will benefit from it as well.

Oh well quite a long lecture sorry ,I am feeling like my college lecturer now

lol.
Praying for you inshaAllah
Do remember me in your prayers as well.