Having Chest Pain And Stress. Suffering From Chronic Depression. Could I Ask A Doctor?

Question: I'm trying to find a doctor for my son. He's 31 years old and has not seen a physician in many years. He smokes, has a lot of stress in his life currently. He's having some chest pain (I think is anxiety), gets emotional at times for what he thinks is no reason he can understand and goes from being in a perfectly good mood to suddenly changing. He's not violent in any way but sees how erradic his behavior is and how it's affecting his girlfriend of 5 years and 3 year old son. He does want to talk to discuss with a physician. My advice was to have him see an XXXXXXX Med physician first that he shouldn't necessarily jump to the conclusion that he's has "chronic depression" as someone suggested. He has not had a full physical for more than 10 years. I'm his mom, and I suffer from depression which is very controlled with medication. Shouldn't he see a primary physician/internist first since this could be medically driven?

He is so worried that he will have to take medication & he hates that idea.. Or any medication for that matter. He gets migraines like I do as well. When they're bad he'll take Excedrin migraine & go to bed til it subsides. How do you suggest I give advice on what may be discovered without freaking him out so he won't go? I live in Chicago & he lives in Prairieville, Louisiana so it's not like I can go with him for support. I told him it's possible it could be medical, I.e. good physical along with basic lab work would be a good start. I have a neice who is bipolar. He knows how "crazy" she can get (she thought she was the queen of England" once. Because the family sees her in a negative light he doesn't want to be looked upon like that.
Any suggestions other than don't panic, get a physical and take it as it comes? Are there possible medical reasons for his feeling the way he does? He's a bit of a loner like I am in that I hold my emotions inward. He gets it honest from me. I just told him last night that I do take Meds for depression. I had not shared that with him before. I want to encourage him but not push too hard. Suggestions? XXXXXXX med dr or general practitioner? Where do we start?