Is this a huge deal!

1999 honda accord, 4 cyl, 4 door, 5 speed.

My mom passed in april, I recently got her insurance money, around 3,300 and paid 2250 for a 99 honda accord in very good condition with about 260000km on it. Anyways, I got pulled over by the cops 5 days after buying it, and turns out my drivers side wheel is coped in. Mechanic didnt know much about body work, as this is what he said it was, but there are apparently brackets on each side holding the wheel, that they are 2 of 4 anchor points securing the wheel, these on my drivers side are completely gone, as he was flaking away the mud that he said is usually around these, they just flaked away as well. I guess thats why I felt bouncing sometimes, like I had left my trunk open or like my muffler or exhaust was hanging off. Anyways, im taking it to a guy they recommended, but they also said it could have cracked the subframe but that it felt nice and solid and they didnt have reason to beleive it had. Im scared! I just blew my moms insurance money on this car, I learned to drive stick, I can finally get my kids around to appointments and to do errands, I finally have a life. I know the guy who sold it to me wont give me anything towards it, and probably wont refund me if the problem is gigantic. But is this a big deal? What are these brackets called? Is it going to cost me a fortune?

thanks in advance, to any help, and also the mechanic said its something even the inspector missed, and that it is something that you dont know is going til its gone kinda thing. And it deff wasnt like that when I bought it. One bad pot hole or bump must have just let go.