I don't want to stop - should I carry on or wait until I'm not in any more pain? I can still just about touch my toes but bending sideways is painful. Don't want to do any damage but would like to get fitter.
It's not pain as in indicating an injury or damage - t's discomfort, often called "DOMS" -
Delayed
Onset
Muscle
Soreness
It means your body has worked, and done something it's not used to doing. This is GOOD!
The best way to assuage it is more exercise - a long walk, a swim, or more of the same gentle stretching.
But when you stretch, NEVER do it with a "cold" body or use static stretches you hold for more than a count of 5. Make sure your body is warmed up - literally raise the temperature of your core by 5 to 10 minutes of all over body movement.
Try a combination of moves such as marching or jogging on the spot - be vigorous enough to get to the point just before you lose your breath - jumping jacks, body weight squats (only do those if you know how to do them with good form) single leg swings - hang onto a door jamb, and swing your leg forwards & backwards, and then side to side across your body - keep it low and LOOSE.
Then go into your stretching routine, and take it sloooowly.
You mention touching your toes - if you are unaccustomed to doing this, don't just bend over. Roll down.
First of all, stand straight and get your pelvis in a neutral alignment - try to feel as if it's a bowl of water and you're trying to prevent the water from slopping out.
Then gently bend your knees ad drop your chin to your chest. Breathe out as you then try to roll down through each vertebra of your spine, until your chest is almost lying on your thighs. Be aware of the weight of your head and keep your neck loose and your head relaxing down. Let your arms drop as your spine rolls down.
When you've rolled over as much as possible (aim your nose to your knee, but DON'T strain) bend your knees a bit deeper, and then try to touch your toes. Leave your fingers on your toes, and GENTLY stretch behind your knees, while keeping the momentum of your torso going forwards - you should feel that if you shifted your weight a bit more you'd fall forwards (but don't do it, jst get that sense of weight forwards!)
It's a lovely slow gentle stretch with the addition of a really nice spine roll, which is great for the flexibility & mobility of the spine.
Reverse the process to roll up. Aim to straighten your knees as you raise your head ie these are the last things you do.