Can "feelings" be intrusive??

for me, it's like there's two folders of my thoughts, 'main thoughts' and 'sub thoughts' and it's like a background voice of my background voice, you know? like so quiet and irrelevant but it's still here and i can try to ignore it but not fully and it feels like it's just really nasty, like it's warring with me, never shuts up and just keeps nagging me with those thoughts

Please how can an intrusive thought be distinguished from our own thoughts ?

does anyone else constantly suffer from intrusive thoughts? it makes my head ache & i can barely think straight.