all my text messages on my iPhone 6s just disappeared on its own?

all my contacts are still there but my messages are all gone! My iPhone 6s has had a lot of glitches lately and this isn't the first time this has happened. I already went through this a few days ago but had lost my contacts too! My contacts are still here but for some reason in contacts my own contact isn't there! I think the glitches have to do with the fact that I am out of space and my photos are taking up 44Gs! I never drop my phone and I don't know what to do!