Good advice from several of the previous posters!
OP, has it always been your dream to learn how to snowboard? In that case, just keep on practising, and you will improve. Take more lessons.
If you just want to be able to go down the slopes together with your family, I agree with those who suggest you try skiing instead. Many people find that easier. I am not very athletic, but I have been downhill skiing succesfully in both Europe and the USA.
My friend once went on a trip to the Alps, and she really wanted to learn how to snowboard. It never worked out for her, and she switched to skis after half the week, and she found that to be easier.
Whether you decide to keep on with the snowboard, or try skiing instead, it's important that you take lessons! It can be in a group or with a private instructor, but lessons are really important.
And, whether with snowboard or skis, it's completely fine to stay on the gentler slopes for beginners. Those slopes can be so much fun! My favourite ski slope in the world is one that is not very steep, but very long.
Good luck, stay safe, and have fun!