How can I have anxiety with good news?

Recently, I found out my wife is 4 weeks along in her pregnancy? I am ecstatic. We've been trying for awhile now. Then 2 days later I start having heart palpitations. So I go to the doctor and everything comes back normal. I've also had two bad panic attacks. Has anyone else experienced this too? I'm 24yrs old and the blood work, EKG, and stethoscope all came back normal. The doc prescribed xanax and zoloft but I don't want to take those mind tripping pills. Please help thank you