Yep. dry, chalky or not melty = too much acidity. Did you put too much starter bacteria or waited too long from starter bacteria to rennet? Did you wait too long after rennet? Chances are that your cheese was doomed already in the vat. If it's just dry and not chalky, and is capable of melting, then maybe you over-pressed it or cut the curd too small? If not, than I would look into the aging: Was it waxed? Vacuumed? Cloth-bound? Rubbed with oil? Naturally-rinded? What temp and humidity was it at? Did you turn it on occasion?
Do not despair. First cheese is often not a success. I still remember how my first cheddar blew up due to gas contamination. The second came out like a sour chalk at 4 months. It takes a few batches to get the feeling for curd, process speed, cutting and pressing techniques, aging them etc. Many people choose to start with cheddar but it's not an easy cheese (cheddaring process, careful acidification). Moreover, it takes way too long to find out you were wrong. By the time you find out what was wrong with the first one you have several more awaiting maturation with the same error.
I would start with fresh cheese first - just to get the feeling for curd and acidity and to get encouraging immediate results that you can eat and give you confidence about the future. In this list are Chevre, feta, Haloumi, Queso blanco/Queso fresco, and Mozzarella. Heck, you can do 3 of them in a week, taste them, perfect them and move on. Then, do the easy/fast-to-age cheese: Crottin (14 day), Chaource (14-21 day) and Camembert/Brie (21 days). Now that you have a fromagerie at home and you have blown yourself and all of your friends away you feel good about it and can move up to the harder, longer aging cheeses; the basic Tomme, Havarti, Colby and Jack (4-6 weeks, Colby and Jack are like lazy man's cheddars). Now you will be confident about making cheddar. Farmhouse Cheddar is easier and ages faster. move on to classic cheddar, clothbound cheddar etc. At this point you can pretty much do anything; tellagio, Muenster, Romano, Parmesan, Cantal, Comte/Gruyere, Baby Swiss, Gouda etc. Take your time and just imagine how many cheese varieties you can learn at merely just the time you are waiting for your first Cheddar to age!