can i sue my parents for fraud?

a few years ago my parents asked me if they could borrow some money from me to help repair a car they bought a few years ago. i agreed to loan them the money if they made significant contributions to paying of the balance. but it seems they have made very little contribution to what they have borrowed from me' theyve discarded the car which means that all that money was spent in vain and they have decended into alcoholism. they often threaten me with instand eviction and destruction of my property. i intended to return to higher education in my early 20's but thanks to my parents selfish and greedy actions i probably will never get back to a higher education. i originaly had a debt of £3'500 and my parents have taken the same amount. can i sue them and get my wasted years back?