Smoking habit symptoms and conditions

I have taken an oral form of Doxycycline daily for at least a year.
Before, I thought such symptoms were relevant to a fluctuation of bodily chemicals during pubescent growth.
I am now sure otherwise.
During the time between when I was prescribed and today, I would never have known that these things were side effects of an antibiotic.
I'd wake up every morning, take a shower, and feel like I'd vomit if I kept standing. I laid down on my bed and realized I felt way too hot. I'd take off my shirt and lay down in front of my floor fan.......Now, every morning after I take a shower, I stand out in my back patio, 45 degrees, in only my boxers--completely comfortable for as long as whenever.
I have terrible sleep.
I stay up at night thinking too much about almost nothing.
Overwhelming self-conscious thoughts.
Overwhelming.
Sometimes I feel like I have to do simple things manually, instead such movements occurring normally, like auto-pilot.
Walking. A majority of the time I walk, its like my first steps:
bring left knee forward, put left heel down, bring right knee forward.....
Blinking.
Concentration.
Anxiety, paranoia, you name it--
I developed a smoking habit that numbed out all the stress.
I am not quite sure if I was addicted other the occasional crave of a cigarette, but...
Look,
every now and then, because my doxycycline came in the mail, I would have a week or two without it.
I think, antibiotic, right? Doesn't matter right? just like a Vitamin? just take it and whooosh its all good, it does what it does, helps my acne whatever--
during those periods without it, I felt distinguishibly happy and calm and I didn't even crave cigarettes.

As of now, I realize that those were not loony mood swings, and, a multitude of people suffer and have suffered from doxycycline.

Day 21 on Welbutrin XL 150 mg. - prescribed to help stop (light) smoking habit & for depression. I loved it - smoking urges not nearly as strong, more energy, very few emotional outbursts & general sense of calm, happiness & well-being. I haven't felt this good for 4 years. Have tried other meds in past but quit due to weight gain & sexual side-effects. Yesterday I developed HIVES. Damn. Saw nurse practitioner today. She wants me to switch to Lexapro. Told me to start w/ 1/2 a tab @ bedtime tonight. AAaaarrrgh! Anyone have any experience w/ Lexapro?