Weird sensations during meditation

[Ryan_047]

This morning,after I ate my breakfast,I decided to meditate.I was sitting on a chair,straight up spine,hands on my legs facing up.I'm meditating for 30 minutes using the do nothing technique.I usually center myself by breathing deeply a few times.Today I felt a tightness in my chest,and I couldn't breathe deeply because of it(this happens often,but it goes away relatively fast).So I started breathing deeply at a regular pace,and I noticed a tingling and numbness sensation appeared in the middle of chest, above of where the tightness was present,and it has gotten rapidly more intense.

I decided to breathe normally until the sensation would go away.However,it kept growing in intensity and that tingling and numbness sensation made it's way to my head(in the area of the Phone Bone).As it was getting worse,I freaked out a bit and stopped.It has been 10 minutes of meditation.I took a 2 minutes break and started again.This time, the sensation reappeared in my left foot and right hand simultaneously,and yet again it made it's way up the middle of my chest and head(this time the face's muscles were involved too).I also felt like there was something rising up from the base of my neck (kind of like the sensation you feel before vomiting,but not that bad).5 minutes later,I have taken another 3 minutes break.I tried standing up and I felt lighter in the extremities of my body,and also my chest felt heavier.After that I started again,the sensation was there,but not with such high intensity,it was bearable.When my meditation session was over I felt lighter in the whole body and the numbness was gone.

I'm not sick,or taking medication of any kind.Have I done something wrong when I meditated? It's the first time this happened to me..also,for some reason I started to dream a lot at night.. sometimes I have 2-3 different dreams.