Hi Kirsty,
Welcome to Neurotalk. First of all, don't panic - MG can actually be controlled quite well through medication and self-monitoring. Your symptoms do sound like pretty classic MG though - especially your fall weight-lifting.

You asked about weightlifitng - as far as I know it will not "speed up the problem," however when you lift weights you are essentially fatiguing your muscles really quickly through repetetive movements so there probably better ways to build and maintain your strength. The most important thing is that you monitor yourself and don't push too hard. You can really wear yourself out for the follow day too. I'm a member of a MG workout support group on facebook you might want to check out too.

I keep a detailed diary of all my physical activities and how I'm feeling everyday which has given me a whole bunch of insight and lets me give my neurologist really detailed information. In fact, my diary alerted me to something which might help you with your food question. I noticed that when I wasn't working for long periods - I'm a teacher, so I;m talking about summer holidays and Christmas breaks - I was always feeling worse and falling more. It seemed so weird because I was doing less and suffering more. Then I realised that during the normal school day I eat a banana every morning and one at playtime, but when I was home I wasn't eating any. Immediately I added a potassium suppliment to my diet and continued eating bananas. I noticed a difference straight away! Bananas are my wonder food!

You also asked if your symptoms would worsen - there is no easy answer for this. We are all so different. My neurologist thought my MG would be able to be controlled by daily doses of Mestinon and would stay the same, but about two years ago my symptoms started to get worse. My husband was a GOd send during this time and helped me with all sorts of things, including carrying me up our stairs if needed. I've been on steriods and azathioprine now for almost a year and I'm back to feeling great! There is such a huge range of medical options that sometimes it just takes time to figure out what works for you!

I hope some of this helped. It's great that you asked so many questions - that's what we are all here for, to learn from one anothers' experiences. Good luck with everything!
~Kathy
Sorry, I can be a bit long winded at times!