Cannabis :: Lightheaded And Low Blood Pressure

So I started smoking weed around November first time got so high of a blunt i could hardly speak. Smoked a few times after throughout my last months of senior year. After i graduated is when i started smoking more frequently about 7 times a month. Never had any problems would always hot box in my car with a friend and later play some games. I'm not sure what the strain was that we were smoking but i'm pretty sure it was sativa, the reason i say that is because just recently about a week ago i went to an old friend's house to pick up some weed from his supplier since mine was dry. He told me it was outdoor indica which is why im assuming what we've been smoking was sativa. On the drive back home me and 2 other took two hits each from the bong(which by the way was my first time smoking out of one). At first i was starting to feel the high the whole relaxed feeling. About 10 mins later im really not sure, we're still in the car almost to the creek we were heading to everything got really bright and loud, i lost all focus i had no idea where i was or how i got there and i got extremely light headed. I started tossing around looking for a comfortable position saying i needed to lie down. I started feeling really panicky and paranoid as if i was going to die but i remember being more worried about passing out and not being able to drive home and having to call my parents which only fueled my paranoia. After what felt to be minutes but was only second passed i felt better and got up to catch up with my friends. Again i started getting light headed and had to lie down. I later felt fine after about 10 mins but was still really stoned. Afterwards i thought hard on what could have caused me to feel like that and i thought maybe my blood pressure got to low and that's why i felt all light headed with the bright lights and noise. So i brushed it off. I took a break from smoking for about 4 days and decided to smoke again. This time i used my glass pipe, at first i was fine for about 12 mins then decided to go inside. While in my room it hit me i got really uncomfortable and i felt like my heart was trying to pound its way out of my chest with a sledge hammer. I started walking around my room with paranoid thoughts of dying in there and having thoughts of telling my parents to take me to the er, so to try to calm myself down i lied down on my bed and started listening to some reggae. Still having my heart beat harder then i ever felt it beat i started feeling the normal high again about 20 mins later. I've never had this happen before and i don't have any medical issues or mental ones. I've been a little depressed lately with how things have been going in my life but i've had that for months now on and off. So i've come to the conclusion that it might just be the indica having higher amounts of thc then its counterpart sativa. I wanted to have some other thoughts on it.