20-30 degrees of heel may feel like much but your keel ballast have just started working at that point. What you have, as pointed out above, is probably an initial stability issue which will happen if your boat is not very beamy or has a round underbody. You will find that capsizing a keelboat is harder than one might think.
Even my sailing dinghy without a keel surprised me. You step on it and it feels like it will roll over on slightest imbalance. Feels much more stable when heeled under sail.
1978 Gulfstar 50'
Clark Sailing Dinghy 10'