Stay away from Google! And also hugs to you about your cousin , no wonder you're feeling so worried, I can totally understand.

It really is normal for your bub to have extra-active spurts, my DS1 would do that quite a lot and he stilll hasn't stopped that behaviour 4 1/2 years later LOL! But seriously, it does sound normal and it is also normal that your bub has calmed down now and will probably have big sleep after that huge effort. If you are feeling overly stressed about it all, give your hospital a call and tell them what your bub has been doing and explain why you feel worried about it. I'm sure they will reassure you over the phone or even offer to monitor your bub.