There's nothing wrong with starting slowly ... whatever suits you. Quite a few people here eat white potatoes so you may not need to give those up.
Walking while loaded with shopping and rowing are great forms of exercise. I'm not making any promises, but many here have been able to come off the meds you are on. Many people go primal primarily to lose weight or get in shape and never dream that the diet will cure various chronic health problems, especially inflammatory/allergy/immune system related problems.
Best of British!
F 5 ft 3. HW: 196 lbs. Primal SW (May 2011): 182 lbs (42% BF)... W June '12: 160 lbs (29% BF) (UK size 12, US size 8). GW: ~24% BF - have ditched the scales til I fit into a pair of UK size 10 bootcut jeans. Currently aligning towards 'The Perfect Health Diet' having swapped some fat for potatoes.