Hi Juniper. Welcome to the forum and sorry you're in pain. Being female, I can't comment on more than matches my pain, and what I think.
About the pulling to the right side of your anus. I too experience this. I have no idea if this is because of the shape of the rectum changing from pressure on the anus ( here is a Wikipedia link
http://en.wikipedia.org/wiki/Rectum), or if it is because you have to strain (a no-no but sometimes difficult to avoid). My pain has improved and a bump that was there has gone down, since I started using Nifedipine and Vaseline on the outside. But I still have pain. There are other reasons, but go with these first, unless the pain is intense, then don't hesitate to go to your doctor.
The 'ball' sensation I have also experienced. I thought that I might have a Rectocele, but this only applies to women. Someone else here might have some suggestions on that, or if you do go to that link above, try entering 'rectum male,' in the Search section and have a look at what you find. Don't mean to freak you out, but I believe in research as much as possible. Hopefully some of the guys on here will come up with some suggestions too.
You said you have pain in your scrotum and your left leg (did you mean your right leg? Mine is on the right, where it hurts most), and my personal opinion is that this is from constant straining pressure against the anal mucosa. That is why you need to keep things soft coming out. A lot of the folks on here use Miralax - I use Milk of Magnesia, and peri-Colace as this is what I am used to. Very important not to get constipated, drink sufficient water and get fiber in your diet.
The pain in your abdomen: this is more difficult and you should really chat to your doctor about that. I get a lot of pain on the left side, low down, when I get a flare-up of diverticulosis. I have that right now and have been in moderate pain for four days. Not fun either... Ask your doctor. I had an MRI and they could see this.
Hope this has helped a bit. Pain is not nice, but at least you can share it here. Feel free to ask any questions.
Again, welcome!
Em