For someone dealing with obesity, that bp reading seems quite low. What's your current weight?
Your bp is on the low side and you're experiencing symptomatic postural hypotension. Since several of my questions went unanswered, I still can't pin down the cause. What about your age? Any cardiac issues?
Retatrutide itself reduces blood pressure, and when you add substantial weight loss on top of that, the drop becomes even greater. Following major weight reduction from bariatric surgery, at least 50% of patients develop this, so it stands to reason the same would be common after weight loss on reta.
Nearly 4 years ago I began having my vision grey out when standing, and I still get it today — though I did lose 80 kilos. If massive weight loss is the culprit, this could persist long term.
I'd still recommend getting a doctor's assessment and guidance. Options exist that can help, such as blood pressure raising medication when needed, though a cardiologist typically handles prescribing that. Your situation doesn't sound severe enough to warrant it. I won't suggest trying salt tablets unless you've had your electrolyte levels checked beforehand. If reta has you drinking less, increase your fluid intake. Compression stockings may also help.
The most dangerous problem by far is fainting and then injuring yourself when you hit the ground. Usually you get some warning through dizziness or vision changes, so if that's happening, be careful and try to get your head down — for me, simply bending over a bit does the trick. If you remain upright and blood pressure drops low enough for your brain, a reflex kicks in — vasovagal syncope — where your body plunges blood pressure further, making you faint and fall as a means of restoring blood flow to the brain.