Purity

1) I am suffering waswasa regarding kufr and impurity. First when I used to feel I said any kind of kufr statement I used to pronounce shadah agai.then I started getting doubts about impurity also. I felt that I said some thing related to kufr (which I most probably didn’t say) but I tried to resist waswasa and didn’t repeat shahada this time. But when I went to urinate waswasa came that I discharged mani (which I most probably didn’t). Now I started to worry that since I had said words of kufr and now I discharged mani not only I have to repeat kalima but I have to take ghusl also. Then I said since I am not sure I discharged mani so only shadah will suffice. Then the waswasa came that by saying this in a way I accepted that I became Kafir and what if I had discharged mani do I have to take ghusl also after pronounce shahadah?
2) I have read if a person discharges Mani without feeling of pleasure or is not sure whether he discharged mani or not ghusl is not wajib on him. I also have read that if a kafir accepts Islam ghusl is fard on him only if he was in state of janabah. If a kafir had discharged Mani without feeling of pleasure or was not sure whether he discharged mani or not and then he accepts Islam, is ghusl fard on him?