yes, you should take a step back and take things slow. You've been with each other for 2months & right now your relationship is in the "honeymoon" phase where everything is happy & perfect. Your brain is high on endorphins & at such a time everything seems to be in your favor. I would advise you to refrain from doing anything that may harm you & your gf emotionally & mentally later, if things don't go as planned. I say this especially because you want things to go right & don't want to lose her, not to be negative. Also, your gf has depression so take your time to make your relationship reach a steady place & then you'll can get sexually intimate. Of course, kissing & light making out is fine. Just don't indulge in sexual acts. You second guessing this is a sign that you may not be completely ready for this right now.