Help messages app not working!

when i open messages i see all mt text messages but when i tap on one of them it doesn't cycle out of the loading screen.i have restarted my phone 3 is an inspire 4g

i dont know if this matters but the conversation im trying to open has 1,489 txt messages... i deleted ALL the other txts but this conversation.

well **** it now i called att the were shitting idk.called htc friendly but cluless and now im at starting block 1 with a factory restore...