Here’s the thing: magick is kinda like sex in that if you look at the process objectively it’s pretty goofy but when you’re fully engaged in it, it can be very powerful and fulfilling. I promise you every single witch or magician ever has felt like a jackass doing magick sometimes. I still do sometimes, especially when trying new stuff. It’s super normal. Practice and experience helps a lot though and once you get some results under your belt it starts feeling a whole lot less silly. Just keep practicing and experimenting, you’ll get there.
Since you mentioned your brain not shutting up I’d really recommend getting proficient at meditation and maybe trying out some of the gnosis techniques used by chaos magicians. Here’s a neat lil infographic on various types of meditation, their goals, and how to do them (note that empty mindedness is not the only way to meditate!).
Also it’s ok to laugh during rituals. If you feel dumb, then laugh and move on. No point in trying to suppress it, you feel what you feel so let it out, collect yourself, and keep working. I think a really important part of getting good at magick is learning how to shake off distractions and refocus yourself.