Thanks for sharing your concern.
Frequent brushing is not required , but regular brushing is must.
It is best when you brush after meals, but since presently not in your habit. I will say start doing it at least twice .
That once in the morning before breakfast and evening after your dinner. This is very helpful.
when you don't brush and sleep in night whole night bacterial activity goes on cause lots of damage to your teeth.
Do regular flossing for inter dental areas , use mouth wash periodically, don't worry you will be problem free.
Later on, you can visit your dentist
for a small oral check up, if any cavities are found. It can be restored in initial stages only.
Start from now before it gets too late.
Hope it helps, thank you.