Why am I paying only interest on my mortgage?

Hi- I am in a VHDA loan, 300k, Conventional without PMI, 30 year 6.375%

Need help with comparing FHA vs… I will put 10% down on a home with the purchase price of 225K. I can chose either a 30 yr 4% fixed interest loan, or another lender is offering me a conventional 30 yr…

VHDA tax return in 1098? Any other way… We are first time buyers and we are able to pay our taxes on 5 File in January, but I need the 1098 of our mortgage bank. If you VHDA you know if there is…

For the past 3 years I have paid off around 20k a year…but the principal still is 300k. I am only paying the interest.

Why am I paying only interest? When will the principal payments kick in? Do I need to pay more than my monthly payment to chip into the principal? It seems like I am paying all interest first? Does that mean I won’t start paying off my house til year 10 or 15?

And If I am not paying off the principal, I always owe more than what my house is worth! That means I cannot refinance or sell, right?? Suggestions or info is very helpful.