The problem is that you're making it all about YOU.
"i don't like seeing you so tired and stressed and me not being able to do anything about it."
If she's tired and stressed, she doesn't want to hear your whiny *** making it all about how YOU don't like seeing it and YOU can't do anything. When a woman is stressed, she doesn't want to hear some man complaining about what they can and can't do.
"i wish i could hold you and comfort you. the last time i tried to touch you, you shied away. if not for that i would've held you at the park, i don't care if you're sick."
Now you're trying to guilt trip her. 'I'm trying so hard but you're pushing me away!' If she's not feeling well, the last thing she wants to hear is how YOU want to hold her. It looks like you don't care about her feelings; you're making it sound like you're the one who needs comforting. And saying you don't care if she's sick makes it sound like you don't care about her feelings or health - you just want to cuddle with her because it makes YOU feel good.
"try not to be overwhelmed by all the work. take some time to relax and put things in perspective. A goes before B goes before C. its not the end of the world, and you will find time to do it all. think of the solution, not the problem. what must be done shall be done, don't worry about how or when. worrying about the future too much makes you forget about the present."
This is very unsympathetic! All you're doing is repeating meaningless words, and in a tone that makes it sound like you're bossing her around, not offering suggestions! You might as well have said 'whatever; **** happens.'
So, the reason she didn't enjoy your message is because first you yapped about yourself, then you completely brushed away her feelings. Good job. If you're writing to someone who's having a tough time, put some kindness into it! Try something like this next time:
"How've you been doing? I hope you're feeling better. If there's anything I can do to help you, please let me know! I'm here for you if you need me, sick or not. I'm sure you'll overcome this soon!"
And by the way, if you had genuinely wished she would feel better soon, you wouldn't be here complaining about your feelings and how she upset you. Your message probably upset her more. You should apologize, be supportive of her, maybe buy her a present, and hope she forgets about this incident soon. Your goal seems to have been to show her you're a good person, not to actually make her feel better.