Anger toward himself and craving attention

My 5 year old son is having some behavior issues.  We are teetering on whether or not to bring him to a doctor and have him assessed for behavior problems, but are trying to narrow down what is going on with him first.  These issues are very much more so relevant at school than at home.  He does things that he knows he is not supposed to do at school in order to get attention from other classmates or the teacher.  This can range from picking pieces of his food into little pieces and throwing them in a pile on the floor, to sitting incorrectly in his chair, to using the bathroom in his pants.  He is very smart and i'm positive that he knows that this is bad behavior and it is going to have consequences if he does them, but it doesn't seem to matter to him. As long as he is getting some sort of attention.  And if he is not given the attention that he wants to get, the rebellion and acting out intensifies. These actions aren't so visable at home because it is only his dad and I and him at home, so he doesn't have to fight for attention.
The other issue is that he is extremely hard on himself when he fails at something.  This can be something as simple as not tearing a piece of toilet paper off correctly, or coloring something the wrong color on accident on one of his school sheets.  He absolutely freaks out into a tantrum and gives up completely on the task at hand.  This anger isn't directed at anyone else but himself.  It's like he feels as if he has to do something perfectly in order for it to be right....in his eyes.  This is absolutely not how he has been taught.  I believe in learning from your mistakes and also that everything does NOT have to be done perfectly.
He will have 3 weeks straight of great days at school, and then it will just do a dramatic turn to where he is getting bad marks at school every day.
We are doing our best at home to discipline him at home when he does these things at school and at home, and the teachers are doing there best to work with us and him or trying to correct these problems.
Are there any other methods that we could try to turn this around and show him that he's not going to get the kind of attention he is wanting by acting out like this, or is it time to turn to the professionals for their opinion?
Thanks for all of the opinions in advance.

[Sandman2]

    First, as a retired elementary school principal, I can tell you that there is nothing you can do to discipline him at home for what he did at school.  He is much to young for that kind of a cause and effect relationship to happen.  It probably only makes things worse.  At his age discipline has to be immediate, and consistent, and short.  If the school is not doing that - then that is a problem.
   However, my first question would be what grade is he in and when is his birthday.  Some things just don't quite add up.  Making a 5 year old sit correctly in a chair?  for how long, etc.? tons of questions about that.   Actually, a lot of the issues might be answered by his age and grade placement, so please get back to us with that.
   You also might want to investigate a series of books written for the 4-7 year old child and meant to be read with them.  "Try and Stick with It" (Learning To Get Along) is a good example of a book that might really be helpful.  You can get more info here - http://www.amazon.com/Try-Stick-Learning-Get-Along/dp/1575421593/ref=pd_sim_b_6
    Get back to us on his age and birthday, and I/we may be able to help some more.

[AmandaMom]

The teachers and directors at his school are disciplining him at school when he does these things.  That's definitely not a problem.  As far as the "sitting in a chair" issue, that's when they put him in time out.  He will intentionally move around a bunch or bounce in the chair or do other things like that to provoke more attention from them.
He is in Pre-K and will be entering Kindergarten in the Fall.
I will definitely take a look at the book suggestions and take consideration for any other advice that you guys have to offer.

[Sandman2]

   Ya, I think that he is "working" his teachers.  An experienced kindergarten teacher won't have those problems.  I do want to repeat.  Disciplining him at home for what he does at school is not a solution.  However, you can try and reinforce or teach good behaviors at home that will help him at school.  The books will help there.
   It does sound like he is age appropriate.  The fact that he can go 3 weeks straight of good days and then melt down, seems to indicate some event at home or at school that is a contributing factor.
    Since it is near the end of school year.  I probably would wait till next year to see how he does in kindergarten. And I make this recommendation because you said the problem is almost completely in school.  If it also was happening at home, it would be a different situation.   I would certainly start reading those books and reinforcing the behaviors that they talk about in books.   And its always good to try and get him involved in some activities like soccer during the summer.  Hope this helps.

[AmandaMom]

Thank you for the comments.  He is really a great kid, and i've only thought that these issues were minor until the daycare had a conference with us about it.  I will definitely check into the books and take into consideration your advice about not disciplining his actions at school...at home.  I completely understand the mentality behind this and will start practicing it.
He is very active socially with friends and relatives and also does extracurricular activities such as flag football and soccer.  I think we're doing T-ball next.  He loves sports and is actually really good at them for his age, so we plan on keeping him involved in things like this and summer camps.
I can't help but think that something at school triggers these spells that he has.  We have a very stable home life and haven't had any kind of scenarios that I think would trigger problems.  I don't think so anyway, but I guess you never know how I child perceives things sometimes.  All in all we are a very happy family and I hope that with this guidance and some prayers we can get over this little speed bump in the road.  Thank you very much for your advice.