All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
All the jurists are agreed that Al-Faatihah is the only part of the Quran that is obligatory in prayer. So, any other part of Quran you read after Al-Faatihah is Sunnah. So, the praying person is rewarded for acting according to the Sunnah but his prayer is not nullified if he misses to read some Quran after Al-Faatihah.
Some scholars believe that the person who does not read (or forgets to read) some Quran after Al-Faatihah, should perform two prostrations for forgetfulness.
On the other hand, there is evidence that reading one verse after Al-Faatihah is sufficient. Al-Daaraqutni reported from Ibn ‘Abbas that “He read Al-Faatihah and one Ayah (verse) from Chapter Al-Baqarah in each Rak'ah.”
So, your prayer is valid and you comply with the Sunnah if you read some Quran in addition to Al-Faatihah (one verse or more).
Allah knows best.