Wondering if my "natural" 6.5 hours/night sleep is enough.

Something I've been trying to figure out - they say most people need 8 hours of sleep. I naturally wake up after around 6.5 hours of sleep. I'm wondering if this is because that's my true biological need, or if it's from decades of broken sleep?

Some possible relevant info:

• I take forever to fall asleep; typically minimum of 30 minutes, 60 is normal.
• I naturally wake up around 6.5 hours after my bedtime, often right before my alarm clock, but I do NOT feel rested and energetic.
• If I get less than 5 hours of sleep I really feel it.
• "Sleeping in" for 8 hours feels good -- for a couple days. After 2 or 3 days of 8 hour nights, my sleep quality completely tanks and I have super restless nights until I return to a 6.5 hour night.
• I'm in my mid-40s and I have started snoring, but do not otherwise have any of the symptoms of sleep apnea.
• Sleep has never been great for me, going back to childhood. I often wake up and it's exceedingly rare for me to go the full 5-6.5 hours of sleep without waking up at least once. I can probably count on one hand the number of times I've fallen asleep quickly and have said "wow, that was a great night of sleep."

So, I feel like my natural optimal sleep time is 6.5 hours, but I don't feel rested and I wonder if I'm shortchanging my sleep. But I don't know how to get longer sleep long-term. Make sense?