During thashahhud I’ve always been saying:

التَّحِيَّاتُ الْمُبَارَكَاتُ الصَّلَوَاتُ الطَّيِّبَاتُ لِلَّهِ ، السَّلامُ عَلَيْكَ أَيُّهَا النَّبِيُّ وَرَحْمَةُ اللهِ وَبَرَكَاتُهُ، السَّلامُ عَلَيْنَا وَعَلَى عِبادِ اللهِ الصَّالِحِينَ أَشْهَدُ أَنْ لَا إِلَهَ إلاّ اللهُ، وَأَشْهَدُ أَنَّ مُحَمَّداً وَرَسُولُ اللهُ

but today i saw in islamqa.info that the soundest version is: 

“At-tahiyyaatu Lillaahi wa’s-salawaatu wa’t-tayyibaat, as-salaamu ‘alayka ayyuha’n-Nabiyyu wa rahmat-Allaahi wa barakaatuhu. As-salaamu ‘alayna wa ‘alaa ‘ibaad-Illaah is-saaliheen. Ash-hadu an laa ilaaha ill-Allaah wa ash-hadu anna Muhammadan ‘abduhu wa rasooluhu ” 

So have I been saying it wrong this entire time? Were my prayers valid? Is it okay to say one of these versions and not just that one?