It took me a good six months to get used to barefoot shoes, and I would say, as others have, get some zero-drop shoes and get used to having no heel at all. Your body cannot change or transition to more natural movement unless you bin the heel on your daily footwear. Also, if you keep providing a lot of cushioning underfoot, the body thinks it can get away with coming down hard on it, if you replace that cushioning with a few millimetres of rubber, however, you have to think twice, and you are then forced to relearn how to move in a way that doesn't cause you discomfort or pain.
You'd want a barefoot shoe that has between 3mm to 8mm of sole thickness maximum, good flexibility, and good width. Toes need to be able to flex. If the shoe is squashing you anywhere, in any place, then it's not right. I transitioned with a pair of Vivobarefoot Lucy, (old model now) 3mm sole + 3mm insole (I left the insole in, the large gravel on work's driveway was just a bit too much for my wincing soles without it.) and a pair of Vibram KSO's. I didn't start gradual, I wore the Vivobarefoots in the office on a daily basis - they were black so I got away with this.
Just being in flat shoes every single day, sitting down, and getting up now and then, walking to the kitchen and back, then going for short walks at lunchtime each day helped me transition. I'd also go for very short jogs in the VFF's or Vivos on some days, a minute or less, but always stopped when I got calf-burn! I'm not really a runner, and rarely run, but it was nice to feel such light shoes on my feet for the first time, after years of clumping about I found it liberating.
For a couple of years on and off after transitioning though, I got recurrent neuroma-type pain from around my 2nd metatarsal on one foot, it was like a bruise, like I'd stepped on a big stone - some days that had me limping. In retrospect, I think that was in part due to my feet previously being cramped into too-narrow shoes, a thick callus above the 2nd metatarsal which needed to be got rid of, and my foot bones just not being used to moving up and down freely, thus inflammation and soreness. After a while, I sold my original pair of VFF KSO's, when I realised they were too narrow for me and went for a pair of VFF Speeds in the men's sizes, which had more width in the toebox, which helped things.
It's been over four years later now and I have no issues with walking or running about in barefoot shoes. (Unless, of course I unwittingly buy a pair of shoes that are too narrow in the toebox for me...but that's on another thread...)
What I'm saying is that don't let the attacks of soreness put you off barefoot, your muscles will ache and complain because it's all new, feet muscles have to be very strong to take the loads they do, they become very tough and rigid from load bearing, and any change in pattern can cause them to flare up. If it happens, don't worry, it's not the end of your barefooting ventures.
What I would say to you -
- You mention your achilles. Stand barefoot and upright on a flat floor and feel how your achilles tendons are. If they feel like they are being pulled, then they are shortened from wearing shoes with a heel rise, (most of us had that at the start) and might be in part to blame for the attacks of bursitis / tendonitis when you are walking. Achilles tendons are the toughest muscles in the whole body, and lengthening them takes time, they are a bit different to other muscles. Walking about without shoes, or just wearing nothing but zero-drop shoes every day will help them stretch down gently over a long period of time.
- Take a look at your stride when you are walking, your pain suggests that you are jarring your heel, perhaps you are taking too long a stride and need to reduce it. Also, it's natural to land on your heel when you walk, but with barefoot shoes you do this less firmly, and with your midfoot almost on the floor as your heel comes down. You can only do this if you shorten your stride a bit. As there weren't many videos about when I started wearing minimal shoes I got it wrong for several months, then got it wrong for several more thinking I had to 'forefoot strike' while walking. Thank goodness for videos now!
VB has a useful video on walking technique -http://www.vivobarefoot.com/uk/learn/the-skill-of-movement/walk-before-you-can-run
Xero Shoes also have something very helpful to say about it -http://xeroshoes.com/barefoot-running-tips/how-to-walk-barefoot/
Hope the heel pain is lessening for you, anyway. Let us know how you get on.