upper arm/forearm ache

Hi
I am a 25 year old rock climber with a good physical athletic build.Have been climbing for 5 years and after 6 months of climbing I started to develop a deep dull(debilitating) ache in my left arm from my shoulder to my elbow/upper forearm.The pain only comes if I climb 2 consecutive days in a row and starts up almost immediatly.The ache will stay around for about 30-40 minutes and will then gradually fade out.During this time I am in a huge amount of pain and am at the point of being nauseus and hyperventilating.I am unable to do anything with my arm due to the pain and assosiated weakness.If I have a rest day between climbing I have no problems at all and wouldnt even know I had some sort of injury.Have been to specialist who ruled out lateral and medial epicondylitis but couldnt figure out the problem as he couldnt reproduce the pain.I have a basic understanding of upper limb anatomy due to my online research trying to figure out what is causing this.The deep ache feels like it is in my brachioradialis(under)/pronator,mid bicep and upper tricep(maybe teres minor?)
Some things that dont feel right in my body are:when working with my arm above my head my rear shoulder(cant figure out if it upper trapezius or supraspinatus or teres minor)gets VERY tired Very quickly.almost a painfull tired but is fine once lowered.I get a dull ache and sometimes sharp shooting pain in anterior elbow area when forcefully pushing something,these are spontanious but the ache can linger for a while but is bearable.when i get the ache, if i push deep with my thumb onto pronator(under brachioradialis)it feels like this is the culprit area.my left pectoral is bigger(knotty, not muscular) than my right and is tender to forcefull pressure.
sometimes if i ice the anterior elbow area for 15 mins after a climbing session i am able to climb 2 days in a row(sometimes).I have experienced this pain pattern before in my right arm but with a weeks rest it never came back??A big thing I did notice is this weekend I was throwing a ball(i am right handed) which i never do and i started to get the same symptoms(deep dull ache) in my arm but not as intense as my left arm when climbing 2 days in a row.my terers minor(i think) was then a little stiff the next morning.
Sorry for the long essay but wanted to get as much detail out as possible.
Hope you can help and please feel free to ask questions for better insight.
Climbing is my lifestyle and not just a hobby for me and this condition is greatly affecting my climbing trips and further progression in the "sport".
Thanks
matt