Vaginismus Stretching with a Tampon?

I have had two boyfriends (still dating the second) and tried to have sex with them, however I can't handle penetration. I have this wonderful gift called vaginismus!

My current partner has a higher sex drive than me and it's hard to keep up, especially when there's a major painful hurdle in the way. I'm slowly learning how to use a tiny lipstick sized dildo to get accustomed to the feeling and size. My boyfriend wants me to practice with my toy more often and for longer, but I just don't have the time to. So I thought, what if I stick it in during the day and go about my life? 😂 But then I realised no, no that won't work; what if it gets stuck? I need a string on it. Then I remembered that tampons existed. I have never ever used one - could I have one in all day (without my period)? So my vagina gets used to the feeling? Plss comment what you think! :)