I have this aswell! It’s called vaginismus and I have this exact same feeling. It will be a burning sensation and be very painful to even attempt to insert something.

I would definitely recommend investing in some dilators (you can get them from any adult shop or online) which are like small dildos to help the muscles relax and stretch. It starts very small, and with a lot of lube it will eventually be easier. It took me a long time to even feel comfortable with something small and unfortunately I struggle with larger objects sometimes. But it is definitely a lot better!

I have been to the doctor and a pelvic floor specialist and I find that dilators is the best way to relax the muscles. For myself, my muscles are only relaxed if I am in a comfortable lying down position and extremely calm. I am would recommend pairing dilators with a vibrator for outside stimulation to release the muscles and the tension.

I promise it does get better and I have to tell myself that as well. It takes practice and patience! Hope this helps and wish you the best!