Cumming regularly is healthy and it can be very hard for some without a vibrator to do.

So it is not cheating IMO as long as you stimulate your ass aswell. Try to use the vibrator less tho and also stop before you get over the edge.

You will need it far less after a while.

Using the right kind if chair can work if you dont mind doing crunches.

If you want to do it on the bed, get a really big pillow and a good thick sheet of plastic, metal or wood(ones where you will never hurt yourself with ofc) and tie it on the pillow with a belt or string.

Pretty nice to ride but you need the right kind of dildo for both obviously.