Part of the problem is you are using beads with the same size hole on both sides. If you look some of the beads or cone heads sold exclusively for flies then see how the holes are sized. Some of the beads have a larger hole in back to allow for the bend.
Being frugal (cheap) I try to do same by buying at the local craft store. Same problem. The only way around this is to buy size larger and then superglue with the thread bump. The other way is by enlarging the back side. On some beads this works and others end up in the trash.
If you will send me a private message (pm) then I check with our resident bead expert on Thursday night (MCFR flytying night). I'll find what size of bead will work on the size 8 hook. Can you send me the hook model or number and brand you are using?