Thermodynamically speaking, the only way to lose weight is to take in less energy than what your body burns. There is simply no way around this physical law!
I can relate to feeling awful after working out. You may want to Google "post exertional malaise," you'll find you are far from alone!
I'm in remission (or cured or ???), but I actually still (sometimes) suffer from this.
I'm stubborn as a mule and exercised almost daily during my worst times with Lyme. I'm not recommending you do that too, just sharing that was my choice and I did survive and I did get better. For me, I felt (and continue to feel) that the bad effects of getting no exercise were worse than enduring the post-workout malaise. I point this out because I've read on other sites "warnings" not to push yourself, or else you won't get better. My story is anecdotal only, but I wanted to put it out there.
For me, walking is one of the last problematic exercises in terms of feeling sick afterward.
When I was very sick, I had a small bouncer (mini trampoline) that I put in my living room by the TV, and I would just gently alternate lifting each leg, sometimes with ankle weights and/or while holding light handweights.
I'll also disclose that I'm heavy (obese by BMI). So I am far from perfect! I know I can't be super restrictive with my calories, I simply crave food too strongly to resist! That is in part why I always kept some activity in my routine, because I was not willing/able to further restrict my intake.
I should also say, depending where you are in your illness and what your overall health and weight are like, this may not be the times in your life to worry over every ounce. Fighting Lyme is a full time job, and you can always focus more on your weight when you are further in your recovery.
Well said, wonko -- I figured my body was under so much strain already just dealing with Lyme that everything else would take care of itself once I was well again and finished with treatment. And whaddaya know, that's pretty much what happened. I did gain some weight when I was ill, partly because my body needed nourishment but didn't have the energy to exercise. Once I could take walks etc. after treatment was done and I was starting to feel better, walking was good -- starting with short distances and a mild pace. When you're ready to ramp it up, your body will gauge the energy available. So eat healthy, sleep well, stroll when you feel like it, and look forward to getting well! (Do talk with your doc about it ... but my doc was focussed on the Lyme and not on my exercise program.)
I empathize - my joints hurt so badly I it was all I could do to stand up sometimes. Before I knew what was wrong with me, I did upgrade what I eat in an effort to reduce the inflammation. Even though food is a weakness for me, I figured I could stick to 1 thing, so I cut out high fructose corn syrup. If it's in something, I don't eat it. That actually cuts out quite a few processed foods, but I just look at that one thing, and I can do that. Also, many years ago I cut out artificial sweeteners, but they make me sick so that was an easy one ;-) I have continued to read ingredients and not buy foods that contain substances I really do not want to eat. It gets easier over time, and over time the brain and taste buds can be re-trained, again making better choices easier. I still love food, and if I really want something I eat some of it (except for the corn syrup!) so I really don't feel deprived at all.
Then, I read an article by Dr. Burrescano, where he says the Lyme bacteria don't like heat, and they don't like oxygen (my LLMD concurs). He recommends light (very light) work with weights, and not many repetitions, just enough to work the muscles a bit and keep the joints moving. No hard aerobics (we call it aerobic exercise but it actually creates anaerobic conditions in the body when the supply of oxygen is depleted by the work the muscles are doing). I joined the local YMCA and they also have a whirlpool and a sauna so I do light weights, whirlpool, sauna. Sometimes I swim a few easy laps, just for enjoyment. I believe all of this has helped with my Lyme conditions. I used to walk a lot; when my knees recover someday I hope to resume.
I also take very seriously the recommended timings and conditions for the medications I'm on. If I'm going to beat this disease I want and need every pill or supplement I take to do the most it can do. So, that puts a crimp on my food intake when I need to take something at 6 that requires an empty stomach, and so no snacks after 4 and then no dinner until 7! It's hard for me, but I focus on beating the bacteria and feeling good again, and it gets me through. Also, I have upped my water intake considerably for the herbals I'm taking, and I think that helps a lot.
For me, I do what I can do, I don't push too hard on the physical exercise, but I do some, and I try to give my body the best nutrition I can in order to support the fight against this infection. As a side effect of my determination to beat this bacteria, I have lost about 30 pounds over the last 6 months (and I need to lose more, so losing weight is a good thing not a problem). This, for once, is a nice side effect!