I always enjoyed the contact of the ruck, and at the time you don't really think about it when you dive in. I got a serious split lip in a couple of games because players get too violent, but this was juniors and you do get some stupid tw*ts at 16-18 yrs old.
Rugby is not your usual sport. You know it will hurt, but the key is not to take contact, but dish it out. If you don't understand that concept or don't like pain, quit now and play soccer, or maybe netball or play with some kittens.
My advice is to time your dive into the ruck if you are coming in late, if you are setting up the ruck all you can do is cover yourself as much as possible i.e hands over head etc and you should be ok. You have to keep yourself safe and also make an impact in the ruck.
Just release the ball early and hopefully you won't have been daft enough to isolate yourself with their forwards bundling you.
I used to play in the backrow and also in the backs as i was too fast for a typical forward and we needed pace in the backline. However, i tended to find i got more injuries playing winger and centre than i ever did intentionly in a ruck or maul. These were injuries sustained by spite rather than by mistake. I once got poked in the eye by some arrogant tw*t who decided he wanted to have nails like a girl. He was a 400m runner for england juniors and i was just as fast as him and after i had stopped him doing his usual trick of scoring, he got ****** of and decided to stab my eye out.
I used to get bitten, scratched and that kind of thing as a forward, but you simply give it back to the opponent when you can see it is safe to do so. Rugby is all about giving and giving back. Some players decide to fight fire with fire and get dirty, whilst i never tended to do that stuff as you can give away stupid penalties, it pumped me up that i would give it back to them by using my pace to test their defence. I was occasionally the the 'vocal' captain of the team and i think it is best to lead by example. Any player can kick, punch or bite but not every player can hurt a team by scoring points.