For now I suppose pain killers and hope that it gets better. If it doesn’t or if your symptoms worsen doctors.
As for the haemorrhoid - there are the usual creams and over the counter items. If it doesn't disappear you should go to the doctor.
Drink plenty of fluids and eat food that's not going to upset your stomach.
Well these things do happen but they needn’t. A haemorrhoid and bleeding - I love anal but I wouldn’t do it if it caused this!
Bleeding is not normal, least not if you're doing it right.
Lube - everything and everywhere and reapply as required. Thicker lubes are better - but remember that oil based ones will perish condoms.
Foreplay and practice - your bum needs warmed up and you need to be experienced before anal sex/play with a partner.
Relax and zen - you’ve got to be relaxed, comfortable and trust your partner. I will stop a session if my body is not playing ball.
Your partner needs to be thoughtful, gentle and careful - jackhammering will likely lead to pain for you in the future.
I’d also say I expect anyone who I let near my bum be willing to let me near theirs. Only by having experience how it feels will they adequately understand how thoughtful, considerate and careful they need to be. If my partner wanted to have anal sex with me but vetoed me touching them... then absolutely no way.