Interval work including wall balls

I didn't think today's wod would kill me like it did. But it did:

300m Row,
25 KB Swing (53#),
20 Wall Ball,
15 burpees
Rest 2 minutes between each interval repeat for 3-5 intervals

I have no endurance whatsoever. Although the number of seconds escape me, my time went something like this:
Round 1: 4:XX
Round 2: 6:XX
Round 3: 7:XX
Round 4: 16:XX

Sixteen minutes?!?!?! Let me rehash the last round. The row was ok, I managed only a 1:50/500m speed but it wasn't exhausting. The KB swings were extremely hard on my grip and my abs. It was taking a lot out of me to keep my core tight, and my back was starting to feel the strain as it tightened up. I had to break it up 10-5-10, which is sad since i did the first two rounds unbroken. Then I had to do my nemesis: the wall ball. This one was extremely tough, and I started to feel that old familiar tingling pain in my left shoulder from the tendonitis. I did four, then two, then four again. I had to rest for a little bit, trying to breathe deep and prepare myself to go all out and just nail the last 10.

The whole time I was doing this last round I kept trying to tell myself, "You can do this! You can rest later! You're stronger than this!" I'm trying to become my own mental coach, so I tell myself what I would tell some one else.

So I pick up that ball, and I think I did five and then quit. I waited only a second, picked it back up, and then finished it.

Then there were the burpees. I was trying to do good form, but my shoulder at this point is really starting to protest. I start out trying to bang them out three at a time, and I think these were the slowest burpees ever. The pain in my shoulder really weakened me, it wasn't responding like I wanted it to, and I really couldn't push it. When I finally finished the last one I saw the time was 34:XX, and I had started out at something like 17:XX.

I'm a little frustrated that the shoulder pain is back, it's been so long since I've experienced this I almost forgot what it feels like. Guess I will have to ice and massage, the usual stuff. This pain is a little different than what I was experiencing before feels a little more precise and in the front of the shoulder, not sure what's going on but I'll make sure to mention it to Dr. Bills when I see him next week.

I think I might now know why I hate wall balls and can't seem to really improve upon them. If my hip muscles are as tight as everyone tells me they are, then it's no wonder I can't improve. Like my shoulder, if my hip muscles are always tight I can't really control them. If they're always flexing, then I when I work out I can't flex them any more then what's currently going on. If I can't push them, then they can't improve. I've noticed steady increases in my strict press once I took care of my shoulder, so now I hope that dealing with my hips will lead to unprecedented gains in wall balls and other squat intensive movements. When you think about it, that's a lot of movements. Perhaps the world is about to see Adam break through PR's like he's never done before? It's exciting to think so.