I don't know why I have this certain doubts about Allah.
Even though I know that I shouldn't have this doubts as a shia or as a muslim. It is really I thought for me or is it only from shetan what should I do when I have this doubts. How to prevent my self from falling into doubting allah swt.
I know there is no god except Allah. I have all dalil ( proof) scientific , philosophic etc but my heart is not accepting Allah existence.
I’m so confused. I don't fill the test ( khushu khuzu ) of my salat. When I try to pray it feel that No one listening to me. It like I’m speaking alone.
So can you please help me?

Recite sura naas when ever u have doubts the doubts will fade away. If by reciting once does not help recite once more. It works with me and many have tried, the doubts of Shaytan fade away.

Food be carful of what you eat. Eat as much as halal food you can.

Avoid doubtful food and recite this Dua in your Salaat at least once
Daily in your qunoot
Holy Quran 3:8
——————
رَبَّنَا لَا تُزِغْ قُلُوبَنَا بَعْدَ إِذْ هَدَيْتَنَا وَهَبْ لَنَا مِن لَّدُنكَ رَحْمَةً ۚ إِنَّكَ أَنتَ الْوَهَّابُ

[Who say], "Our Lord, let not our hearts deviate after You have guided us and grant us from Yourself mercy. Indeed, You are the Bestower.

I don't know why I have this certain doubts about Allah.
Even though I know that I shouldn't have this doubts as a shia or as a muslim. It is really I thought for me or is it only from shetan what should I do when I have this doubts. How to prevent my self from falling into doubting allah swt.
I know there is no god except Allah. I have all dalil ( proof) scientific , philosophic etc but my heart is not accepting Allah existence.
I’m so confused. I don't fill the test ( khushu khuzu ) of my salat. When I try to pray it feel that No one listening to me. It like I’m speaking alone.

You need to increase your knowledge by reading books, listening to lectures and visiting cemeteries
Think about your beginning and end. Dedicate time to reflection and pondering
Associate with scholars and the learned
Have a positive atmosphere around you that reminds you of Allah
Increase spirituality by visiting shrines of holy individuals such as the Prophet and his family
Keep praying to Allah for guidance and conviction
This certainty in the heart is not a process that comes through intellectual reasoning but rather a private journey

I don't know why I have this certain doubts about Allah.
Even though I know that I shouldn't have this doubts as a shia or as a muslim. It is really I thought for me or is it only from shetan what should I do when I have this doubts. How to prevent my self from falling into doubting allah swt.
I know there is no god except Allah. I have all dalil ( proof) scientific , philosophic etc but my heart is not accepting Allah existence…..
I’m so confused. I don't fill the test ( khushu khuzu ) of my salat. When I try to pray it feel that No one listening to me. It like I m speaking alone….
So can you please help me?

I totally understand what you are talking about. Indeed Allah is Great and He will never let you down. Try to keep wudhu at all time if possible, also increase the saying of the following:
1. Auuzu billahi minashaitan Rajeem
2. HASBUNALLAHU wa ni IMAL WAQEEL
3. Laa Hawla walaa quwwata illaa billahil aliyyil Azeem