Hi, GOW--I'm a couple of years older and grumpier than you but months earlier in my recovery. (A couple of days past two months). My OS had told me that although the "standard" time post-op for allowing driving is 4 wks for the L (for automatic transmissions), and 6 for R, or L with a manual transmission & clutch. I'd imagine it's even longer for a bilateral. But he also said that if driving hurts, you can't switch pedals and brake hard and fast enough in an emergency. And if you are still on regular opioids (which you apparently no longer are but your initial post didn't reveal whether you were at 4 wks) you won't have the reaction time and alertness necessary to be a safe driver, period. I take Norco only just before a PT session, because I get driven to and from there by the center's van; otherwise, I'd cadge a ride or get a taxi. And I wait till it wears off before I handle a car, knife or hot appliance. If you have to choose between driving and pain control, pain control MUST take priority--you'll find some other way to get there safely or it's not important enough for you to go. (For instance, here in Chicago we're lucky to have Peapod for online grocery shopping--the driver will even put your purchases where you tell him to). It's always a good idea the first few times you drive to have a passenger with you who can take the wheel if need be.
As to the clicking and the effect of weather on your comfort level, my OS' hospital's "joint replacement class" told us in advance to expect that on occasion, even years post-op. If the clicking is more of a clunking and feels unstable or intrusive, you might have the wrong size implant. Instability can also be due to muscle weakness (and paradoxically, tightness), especially your quads, glutes and calves. Talk to your OS about a return to PT or some home exercises (done only to a point short of pain) to stretch and strengthen your muscles. Going downstairs and downhill is always shakier and more uncomfortable because it involves "eccentric" (pronounced "E-centric") muscle contractions which require more strength and stability--that's what those step-down exercises later in the course of PT are for. It is not a sign of a failed surgery, nor is it a badge of dishonor, to use a cane--in the seniors' version of "Our Bodies, Ourselves" the author suggested it makes a marvelous "accelerator," and you'll notice that even young and healthy hikers often use canes, staffs, or hiking poles for support and power on uphill climbs and to serve as brakes on descent. (It also gets you a seat on the bus, or helps you hook on to the strap or top rail if you have to stand).
Not all joint pain is osteoarthritis--you can have pain without bone grinding bone. Swelling and stiffness is your soft tissue's way of protecting your joints from what it perceives as further injury. And there's a difference between the joint and ligament pain you get from overdoing, and the muscle soreness the day after increasing the intensity of strength training (the latter due to microscopic tears in muscle fiber that repair themselves and then some with a day or two of rest). But if it hurts WHILE you do something, don't do it, at least not at that intensity. Stop or at least back off a few notches.
I've learned to appreciate the difference between pain and discomfort. And, having suffered from clinical postpartum depression (and being sandwiched between two generations of chronic clinical depression sufferers), I am very careful not to toss around the term "depression" lightly. We have ample reason during our recovery to often feel misery, frustration, discouragement, despondency and even despair--but those are logical reactions to a truly stressful situation. Clinical depression often happens with no situational triggers whatsoever and is caused by biochemical imbalances in the brain and endorphin levels in the blood and the relationship between the two. Counseling and spiritual assistance helps in both despair and depression, but depression almost always requires pharmacological or other medical intervention in addition. Depression is a life-threatening illness and not to be trifled with. Despair post-op is normal. Depression is NOT. If you experience feelings of worthlessness and intractable hopelessness and see no reason to continue living, CALL A DOCTOR IMMEDIATELY!!!