oftheherd1
Senior Master
Well, first off, if it's really bothering you emotionally/mentally and it continues to be on your mind all the time, you may want to talk to a therapist or counselor about what happened. Being in serious danger can be traumatic, and it might help to have someone to talk to about it.
As far as your actual question.... running is a great defense, as you saw, and a great way to build your cardio. If you hate running, mix it up with other cardio activities like riding a bike or jumping rope. There's a lot of gear you can get for strength training, but crunches, push-ups, squats, and leg lifts are all totally free, as is hitting the bag you own.
Mook jong made a good point about how you can injure yourself punching someone if you're inexperienced. He recommended palm strike; another good option is an elbow strike (tip: don't hit with the point of your elbow, but right below that, at the top of your forearm). You can elbow strike the nose, chin, side of the head, even the gut. I'd recommend practicing some kicks to the knee and groin level too.
Beyond that, just, go to class, learn your techniques and do some sparring.
Very good point about seeking help if needed. Of course, professionals are usually the best ones to talk to, but sometimes, fellow martial artists can be of help as well. The 'been there done that' understanding can help. You may have noticed that you have been complimented on that several times here already. I told you earlier that you shouldn't expect to be able to show Superman a few tricks after only a couple of months of MA training. Nobody likes to back down. But knowing when you are in more danger than you can handle is a precious gift. Even more so the understanding that sometimes you may need to run (retreat: military practice how to do that, did you know?) to be able to fight another day. You can't fight if you are dead or bed-ridden. That's why military, although they don't like to, do practice how to retreat with the fewest casualties possible. It allows the then continue to enjoy life and fight another day.
If you were certain that was your best option at the time, it was. Don't feel bad. If you have since changed your mind, be sure you know how to bring a successful conclusion to the problem if it happens again, instead of just beating yourself up now. But Watergal's point is right, are you obsessing on fear or shame? Fear is a survival factor. Shame is self defeating.
It's OK to make mistakes sometimes if you learn from them. In my life I have learned a lot.