Sounds to me like you should consult a doctor for this answer!!!

If possible find a doctor who specializes in athletes and/or sports medicine because they'll be able to give you the best recomendations, but be wary of anything you hear in an open forum like this when your health and life could be at risk.

The only advice The Pimp can give is this:
With asthma, be aware of your enviroment and the conditions within your gym. Such as air conditioning, humidity and chemicals in the air. If it is a mere inconvienance, then change what workout you are doing if a mild attack happens or simply slow it done unable you begin to feel comfortable again.
Diabetes is a different matter and brings the most risk. Are you a type 1 (insulent dependant) or type 2 Diabetic? If you are type 1, it is best to have a training partner who is aware of your condition and can ideally help if anything happens to you. Type 2 all you really need to be aware of is your blood suger levels and fainting.
Other than that, all I's can do is go to a Traditional Chinese Medicine practitioner and ask them for dietary advice and what you can do to help balance all your levels.
Berst of luck to you, dear Axel.
Peace
The Pimp NeonBlack

That is good. You know your weakness and have strived to quell them. I's salute you for such an endevour.
No other advice can truly be given without knowing you in the flesh and the rigors that you put yourself through duing the course of your regiments.
All that can be said, if you have not already done so, is to provide a list of emergency contacts and procedures to the venue in which you train in case anything sudden and untowards happens to you whilst you are exercising.
Nothing else can be said except: May good fortune be upon thee, dear Axel.
Peace
The Pimp NeonBlack

Not quite. Some gyms do and some do not. It has become a trend of late though that the Gym's insurers ask them to do such things to cover liability issues.
I's have been to some gyms where people have literally broken their limbs training and the gym does is hand them a bandage and call them taxi to the hospital. Very sad and very wrong behaviour.
But it is good to know that your gym requires such things of your, dear Axel. Best of luck to you.
Peace
The Pimp NeonBlack