Struggling with intrusive thoughts about death and the grave - need advice

Assalamualaikum, Lately I’ve been struggling a lot with trying to understand death, especially what comes after and the state of the grave. My mind keeps circling around things I can’t make sense of and I get intrusive thoughts that even lead me to doubt aspects of Islam, even though I know what the deen teaches. Sometimes I get intense anxiety where I’m convinced I’ll end up in hell or face punishment in the grave, despite being a practising Muslim. Small changes to my usual routine make me feel overwhelming guilt. For example, I usually read about six pages of Qur’an every night - if I read less I feel awful. I try to do eight rakat of tahajjud; if I do fewer I feel like I’m losing myself to the dunya. I stopped listening to music, and when I do I feel like I’ve committed a serious sin even though I’m not sure where the line is. These thoughts and doubts have been going on for about a month. They got very intense for a while and then eased a bit, and I’m worried they’ll spike again. I make dua every day asking Allah (SWT) to remove them and let me live happily in what’s halal and pleasing to Him. I can’t enjoy things anymore because anything that isn’t direct worship feels pointless. I’m living life like I’m only remembering it instead of being present. I need help - I don’t know how to deal with or fix this. JazakAllah khair for any advice or duas.