Like many of the others said, GOOD JOB...period.
You did so many things correctly
1. Had air on
2. DId not have tank positioned in such a way that it would significantly increase your chances of getting knocked on the head by it.
3. You had your reg in your mouth.
4. I am going to assume you had your BC inflated
5. You had your mask on prior to approaching water
Learning experience is the key. You now know that you will always do the above 5 things in the future, making your future dives all the more safer. You also have first hand experience of the value of the buddy.
As for the yelling, well, everyone is allowed their bad day. I guess it was the instructor's friend's day on the dive you had the experience on.
In hindsight, you could have just rolled on your back with an inflated BC, and even float into a little deeper, waist deep, and potentially dug your heels in and waited things out. You could then hand signal to shore for help. (Again, this is hindsight)
If you had to get out on your own, like others have said, you could have pointed your head to shore, while on your back, and used your legs and heels to push your way up onto shiore as far as possible. Then a rolling technique might be the way to go.
Considering being face down and trying to get up, the fins would have severely limited your ability to dig your feet down to get up from a face / belly down position without loosing one or two fins. Koodos to you!
No matter what, hold your head up high on this experience. I am sure that if you put anybody else in that situation, several things could happen that would put anybody in dire need of help. For instance, being knocked off the feet could land someone's back on top of their tank really really hard. This could lead to getting the wind knocked out and gasping for air, all the while trying hard to not loose the reg and trying not to drown. I am sure the fall would leave a nice cool temporary tattooo bruise of the tank on the back, too! Nice temporary conversation piece to share a show and tell with the close friends / family and the significant other.
Other horror whatif's include getting knocked on the head by the tank (OUCH) and potentially getting knocked unconscious.
So, hold your head up high. You definately sound like you earned your OW C-Card.
As far as having to be able to get yourself up on your own, as someone had been told by their instructor, I don't know. My reaction is bologne! The strongest construction and factory workers, who may be able to bench 200 pounds, ask for a fellow worker to help them carry 40 or 50 pounds for less than a minute with no shame at all. Thats how they avoid (back) INJURY!! We can all "get by with a little help from our friends". There is no shame in it. Or maybe I am just shameless.