If you take 2mg hydromorphone orally it will probably be as strong or even slightly weaker then 10mg oxycodone because hydromorphone has a very bad orally bioavailability.
However if you crush it up and snort it, the bioavailability is higher and it should be a bit stronger then 10mg oxycodone. You can also plug it for a better bioavailability then orally as well.
The best but most dangerous way to use hydromorphone (dilaudid) is by injecting it. It's 10x stronger then taking it orally with a 100% bioavailability and it is considered the strongest more euphoric rush of all opiates. Better then heroin, oxymorphone, and morphine.
However it doesn't have any legs to the high. For a newbie you will have a great rush and then a 1-2hr high. If you have a opiate habit and tolerance you will likely only have a 1hr high or less. I don't recommend IV'ing at all, but if you chose to then please use a micron filter and brand new sterile supplies. If you never have injected before, please don't open that door, it makes opiates 10x more addictive.
I'd recommend for you to wrap it in a piece of paper and then crush it, and giving either snorting or plugging ago.
The best way to avoid addiction is just sticking to orally taking pills. But if the 2mg hydromorphone is noticeably weaker then ur oxy was, consider giving snorting or plugging a go. See if it helps strengthen the effects.
Hydromorphone does have a shorter half life then oxycodone though, so you may notice a shorter high.