Brother, everything you're going through is something a lot of us BHs can relate to. It doens't easier, but you do get better at it.
"I want to tell her that I feel lonely hurt and depressed."
- Tell her, but only tell her if she is remorseful, NC with OP, and attentive to your needs. Otherwise, it will just hurt more. If you can't tell her, tell your counselor or trusted friend instead. You need to get it out.
"Sometimes I hear a song and I feel like it's her feelings for him."
- The affair was NOT about you. It is not personal. This is damn hard to swallow, and really hard to keep in mind when you trigger. Turn off the song when this happens. And again, is she is truly remorseful, talk to her about it. But, be sure you are ready to hear the answer. LISTEN to her, and make sure you coming from a place of wanting to understand instead of looking to reinforce the pain.
"I hear a song he dedicated to her and I'm broken inside."
- Fawk him and anything he did. He slept with a married woman; he doesn't know the first thing about love. He didn't really love your wife and vice-versa. Talking to my wife (when I and her were ready) about their relationship and what it really was (again, she has to come to understand why she did what she did in order to explain it) helped a lot.
"Sometimes I feel like I'm no competition next to OM."
- Then get on the treadmill, pursue a new career, go out with good friends, build better relationships, be better every day, and use your anger/betrayal as fuel to GROW. Prove to yourself you are better and everything you deserve to be.
"Sometimes I want to go home and just cry on her shoulder."
- Again, only if she is truly remorseful. I am not sure what you do to release your emotions, but find a healthy way. For me, I hit the heavy bag and boxing gym ten fold. It helps so much, especially on the days/nights I feel beaten and powerless. Take your power back as a man and go conquer something..join a mud race, train for a marathon, sweat it out...as the saying goes, "the more we sweat the less we bleed." It will do enormous amounts of benefits to your ability to cope with this insanely stressful and damaging event.
"Sometimes I'm just depressed and don't want anything."
- Yup, sounds about right. Take time to take care of your self. This means doing anything that makes you feel good about you. Lay in bed for while on these days, but do whatever it takes to feel good about you.
"Sometimes I feel anxiety like it's all happening right here, right now."
- This is because you are traumatized. I still feel this way!!! Talk to your counselor. Therapy will help you with this along with time.
"Sometimes it feels like I'm the one dragging these feelings after 2yrs and she's back to normal."
- Maybe you are...it's been two years. But keep in mind the only time frame that matters here is your own. It may take 10 years. What matters is you are getting your own IC and taking care of YOU.
"Sometimes it feels like she's back in the relationship because she feels sorry for me."
- I COMPLETELY understand. I realized I was feeling sorry for myself. She can't feel sorry for you if there is nothing to feel sorry for. Reevaluate your position in your own life; are you happy? do you like what you see in the mirror? do you enjoy life? Think about it. If not, think about what it would take for you to have your power back and do it...one day at a time!
Go easy on yourself... just go easy. You're not alone.