Extreme waswasa problem

[Muslimah1928]

Assalamu alaykum
It's me again and you guys helped me before so I was wondering if you had any advice. I have a problem with waswasa.
It started a year ago in wudhu then salah but I beat him in both. Now it's in doubts about Allah most high and I dont know what to do. I'll be making istigfar or salawat and then a thought comes in my head I really try and ignore it but it knocks me
It makes me despair because I know of no muslim that has these doubts to this frequency and intensity and I'm not complaining it's just that I really worry about how bad they are. They are about everything. How do I fight them?
They say that having these is a sign of strong eeman but I'm not sure as I have done some bad things and I need to make tawba but I cant even do that properly.
They come in waves where no matter what I say or do they keep coming and then after the wave is over I really worry I've commited shirk. Can you commit shirk in your heart.
I DO NOT speak them but do I just ignore them and continue saying dhikr no matter what

 

[Muslimah1928]

Also I need to make tawbah. But whenever I feel guilt and try the guilt goes away again. I dont know how to make tawbah properly and what is the difference between sincere and false tawbah.