welcome to HCM.
I can understand your problem.
Ideally you should be getting help from an ortho . doc. but in the meantime, you can splint
the fractured part on a hard board upto the elbow and immobilize it by tying the board with bandages.
pain killers would help . paracetamol
3 times a day or add on NSAIDS.
whether a cast is sufficient or surgery is needed, can be decided by your doc only.
I can't advise on that.
pl. do not delay tio avoid mal-union of fracture.
get well soon.
I hope to have satisfied you. thanks.