HELP!!!! my civic is dying!!

yesterday i was at a red light and when it was time to go the car started acting like it was going to choke out started to idle very low. When i got home going up the drive way the car died tried to restart it and it would turn then die then the "D" light on dash started to flash. I know the light flashing means transmission issues put i have no signs of transmission failure does not slip or make noise. I checked for any loose conections but could not find any. the car starts fine when cold but when i drive it for ten min. then turn it off and try to turn it back on it turns and dies but i notice if i put it in neutral the car starts fine but still wants to choke out when i step on the gas. My question is this really a transmission failure or could it be gear solenoid, torque converter, or some kind of sensor if so, is there anything i could do. I really want to do everything i can before i have to take it to a shop money very tight. Thanks.