GP not treating me correctly

Hi, so last week I went to urgent care centre after contacting 111 about my severe headaches, and they did a full review on me, took bloods, the lot to rule out anything life threatening. They proceeded with observations on me and asking me about my head aches, and said they sound like severe migraines, but they cannot prescribe treatment. They said they will write to my GP and ask them to do an emergency full review as they are effecting my quality of life and rendering me bed bound. They stated the codeine my gp initially presribed me needs to be stopped as they will be making them worse with something called medication over use.  I've read the nice guidelines around migraines and it states if medication overuse is suspected and migraines lasting over 72 hours, then an emergency referral needs to be made to a neurologist for assessment and preventative treatment plan.  I know with state of nhs at the moment with gps leaving practices etc they are over stretched but what's happening now is patients needing emergency treatment are being neglected. My gp normally rings me when I've been to emergency care but this time they haven't to arrange a prompt appointment. If I ring up to make an appointment all I get is ring at 9am to get on the day appointment which I do and they never pick up or I have to wait 6-8 weeks for an appmt. The fact I've been to urgent care, they have written to my practice for me to have an urgent appmt because I need prompt treatment and stop using these pain killers which are making me ill in the long term, and they haven't bothered to ring me is not acceptable. Can I complain about this and if so, how do I? I'm in so much pain, I have 3 kids to look after 2 with complex needs, home educated, they cannot neglect me like this.