I'm a recovering 11B as well. You can get a budget kit going and still find yourself easily under a 15lb base weight. I'd invest in a decent ruck like a ULA equipment Ohm or Circuit but save money everywhere else. A good old USGI patrol bag is rated to 30* and you can buy them off Amazon for $30. Buy a Zlite and a $50 silnylon tarp and you are still under 8 lbs and under $325. You'll still need to acquire a few other items before you're done.
You can find fleeces, shells, etc in good condition at a thrift store. There are several options for cook kits which are well under $20 and lightweight.
Weight goals are often arbitrary but if you set 15lbs as an absolute ceiling for base weight (not including consumables) then it will force you to forgo mostly unecessary gear like hatchets, saws, etc. They sound like a great idea until you find yourself lugging a 50lber up a mountain. This may sound like small potatoes from what you carried in the Army but remember, this is supposed to be fun.
Once you've assembled a basic kit, upload it to this forum and have the members QC it for you. The "you never knows" will add weight quickly to your pack. Members will talk you through your water purification/resupply strategy, etc.
Set up your gear in your backyard and try it out a night or two. Find a 30 mile hike to properly break in your kit to see what works and doesn't work for you; find a hiking buddy the first few times out. Once you have your entry kit dialed in, you can refine it as you go. No point buying a $500 sleeping bag if you find that this isn't your cup of tea.
Not to be melodramatic but I find my ghosts and my angels waiting for me on the trail. I find vets to be a minority on the trail and that isn't always a bad thing. I get to meet awesome people from all walks of life (physicians, professional golfers, hippies, retirees, etc) and I find that to be an enriching experience for me. I spend most days dreaming about the day when I can lay my retirement paperwork down and start my through hike of the PCT. Until then, section hiking and watching hiking vids on Youtube will have to suffice.
PM me if you ever need anything. I still have a few duffle bags of TA-50 and can offer suggestions of what has worked and hasn't worked for me transitioning from Army to civilian camping.