If you are experiencing hypos, it's important to carry a meter with enough test strips, one reason I always carry a meter and strips with my main meter left at home.Also you should carry some treats like jelly babies or preferred glucose supply, like I carry wine gums and a 3 pack of fruit type biscuits. The sweets give you a quicker hit with sugar and the biscuits give a slower release.
As mentioned chocolate is not a good choice as the fat content in it tends to slow the release of the glucose down.
If you are driving, you also need to be aware of the DVLA guidelines for driving and on meds that can cause hypos or you could end up loosing your licence, been there and had the T shirt for another illness. If you do drive remember to test before driving and you need to be basically above 5.0 to drive, if between 4.0 and 5.0 you need to eat a snack before driving. If below 4.0 you have to ea and can not drive for 40 minutes (need to recheck the time span) this allows the food and brain to get back into sync and get out of the confused state.
Everyone can be different in the symptoms they feel when going hypo, though there are common feelings and how a hypo effects one. It could well be worth looking up hypo symptoms as you may well of had symptoms but not recognised they were of a hypo espec if this is the first hypo you have had, though most will recognise something is not quite right. As I have not had a hypo for a very long time, the other week I was out in the garden and felt sick and put it down to doing too much. When I checked I was hypo, the sickness was just a new symptom to me of going hypo. So if you feel different it's best to test to confirm what's happening.