Yes, those are very common symptoms for amphetamine withdrawals. You took away a substance that increases dopamine release and has a dependence, irritability is expect when you take that away. They are a stimulant, which your body became used to, so without it your body hasn't yet compensated for the lack of energy, much like people who quit caffeine after drinking 2 pots of coffee a day for years. The trigger the release of dopamine, the feel good stuff and cause it to be depleted, so you are experiencing less dopamine release, hence the depression. The lack of motivation is due to all of the above.
Amphetamines have to handled cautiously due to how quickly both a physical and psychological dependence can be developed. I take them on occasion to help with school, but I try to limit the use to 2 days per week and when I use them for recreation (higher dose) I try to avoid using them again for a few weeks. I had older siblings that had run ins with amphetamines (crystal and Rx) so I got a little advantage on knowing about safely taking them.
Benzos are a legitimate treatment for some withdrawals. I don't know if they help with amphetamine withdrawal but I'd definitely believe they would help.