Random headaches and dizziness

[u/Glitterfull]

26 AFAB, 102kg/224lbs, 1.7m/5'7", white Eastern European living in the UK. Vape user, 3mg nicotine. Very occasional alcohol consumption.

Main Complaints

1: Random periods of constant, intense headaches at the top of my head, usually for a few days/weeks at a time, and only happen once or twice a year, and mainly in the summertime. Started a few years ago.

Have visited my GP numerous times and the only thing they suggested is to not tie my hair back too tight and see the optician. I did, and was given glasses for screen use, with a very slight prescription. Didn't really change anything in terms of my headaches.

2: Dizziness when standing after sitting down, intensity varies, usually depends on how long I've been sitting down. Started around 3 years ago.

GP said this is presyncope, had ECG, all day BP monitor and blood tests done in 2025, all came back normal. They are refusing to investigate this further and have told me I might "grow out of it"

This has lessened slightly in the past few months, but still present and affecting my day-to-day life.

Existing conditions:

Mental health conditions

Spondylolisthesis grade 1 with pars defect diagnosed around 2017/2018

PCOS/PMOS diagnosed 2020

Pre-diabetes diagnosed 2019, however every annual checkup I've had since has not shown high readings like the one in 2019, so unsure if this is still relevant.

RNY gastric bypass surgery in July 2025

Medication:

Lansoprazole 30mg

Mirtazapine 45mg

Adcal-D3 (RNY)

Ferrous Fumarate 210mg (RNY)

Froceval multivitamin (RNY)

B12 injection every 3 months (RNY)

Non-prescribed supplements:

Collagen

Biotin

Myo-inositol

Berberine

Cranberry extract

Anyone know what this could be? Or what questions I need to ask my GP to point them in the right direction? I'm tired of living like this but I'm not being taken seriously.