The car could be stuck in second gear if it really feels like it is struggling. Try shifting it manually.
It could also be a misfire in the engine. In that case I am giving you a diagnsotic walk though for your situation.
When it talks about getting trouble codes pulled or electrical compoenents tested, Adavancae Auto ro Auto Zone wil do this for free. As far as test where you will need special test tools they also loan out special tool and test kits.
Just use this link below;