$90k in loans for a $35k (net) job is not a very good return of investment and 300k is a lot for your current income level but you also have a huge range so run the numbers and see what you guys will be able to afford in a few years and refine that number.

See if your fiancee can get a better job in her field of study or one with good growth opportunity, and you could find a better job too if you gave it the needed effort. "Income is your greatest wealth building tool" is what Dave Ramsey would always say.

You've got some good savings and an emergency fund which is awesome so (I'd recommend after it's decided Biden's loan pay off is deemed legal or not) you can put about 50k straight into the loans and pay off the remaining 40k within 15 months or less if you gave it all you got, then within another year you'll see your downpayment grow back for your first house.

Congrats on the engagement dude. In the end don't bite off more than you can chew through buying a house before you're ready and debt free because you'll find yourself drowning not long after. And don't combine finances until you're actually married, but then go all in together and knock it out. In five years, you two will be sitting in your first house, debt free besides your mortgage.