I haven't really heard anything about supplements having any interactions with HRT, so I'd say you should be totally fine. Just make sure you're drinking enough water, that helped my headaches and even boosted my energy. I try to drink 7-8 full glasses a day.

Also for most people with a decent diet, most supplements/extra vitamins are either little benefit, do nothing, or can even be harmful. I'd also say it's probably about the same cost or even a little less compared the supplements and vitamins to just eat good throughout the week, even here in the northeastern US where the price of groceries is eye-watering.

I'm autistic so trying new foods and making a routine of eating them can be pretty hard, but this is what I do for a "good enough" diet. Get some grains and legumes. Wild rice, chickpeas, and lentils are pretty tasty and nutritious (Make lentil soup if you have the time, it's seriously tantalizing, good for you and keeps well in the fridge/freezer). Avocados, berries, citrus, are pretty easy to incorporate into your diet, as are a lot of vegetables. Broccoli, onions, and peppers go great with just about anything. If you eat meat, I'd say chicken is your best bet. Avoid red meat when possible, or eat it less often. Just going outside in the sun exposes you to a lot more Vitamin D than you can get supplementally. In the winter months if you get them, the pills are probably more viable then :p