Zoloft and severe Headaches?

So i have been on Zoloft for 3 weeks now and I have these HORRIBLE headaches!  I'm talking going to the ER and crying!  They ruled out spinal headache from my csection and thyroid problems.  They have no idea what is going on.  I have an apt with a neurologist but that is 2 months out.  I have read some people can get headaches from Zoloft but I haven't read anyone getting these types.  It feels like extreme pressure in the back of my head at the base of my skull. (I see a chiro and nothing is helping it) It comes on super fast and takes about 30-60 minutes to go away.  When I get them I am completely uncapable of taking care of my kids.  I also got diagnosed with Vertigo at this same time too.  I'm really starting to freak out!  My OBGYN has no idea what is going on so she said to cut my 25mg pill of zoloft in half to see if it helps.  I did it two days ago and I didn't get as many headaches.  Last night I just didn't take it because I forgot and I only had one episode last night.  I would love to stay on Zoloft because it is helping so much but I can't stay on it if it is causing these.  Does anyone have any thoughts on this or experience?  I totally understand that you aren't medical professionals but I have seen 4 doctors and am going to 2 specialists soon to fix it and they know nothing.  Opinions would be greatly appreciated!