Is my Board to small :(

Hey all!
I was out surfing today in wrotten conditions...onsure winds all day and the place was a mess. Anyway i was really tired after only about half an hour of surfing, alot of people were having trouble getting out because of the conditions but id normally be ok to get out. I just got to tired everytime a set came and didnt have the energy to keep going. Im thinking that my board is too small. I have a 6"8 21 x 2 half which is pritty thick, but today it was pritty much under water bar the nose. Im 6"2 and not far off 15 stone so im wondering if i need a bigger board to make it easier to get around!Im pritty fit so the board being a bit small could be the problem...any thoughts?Cheers
I was out surfing today in wrotten conditions...onsure winds all day and the place was a mess. Anyway i was really tired after only about half an hour of surfing, alot of people were having trouble getting out because of the conditions but id normally be ok to get out. I just got to tired everytime a set came and didnt have the energy to keep going. Im thinking that my board is too small. I have a 6"8 21 x 2 half which is pritty thick, but today it was pritty much under water bar the nose. Im 6"2 and not far off 15 stone so im wondering if i need a bigger board to make it easier to get around!Im pritty fit so the board being a bit small could be the problem...any thoughts?Cheers