Totally keep with it! Do both. When you do weight lifting you retain water at first because your muscles are being strained. Keep drinking plenty of fluids and you'll see a difference. My suggestion is to not weigh yourself daily, especially when you start something new to your routine. When I started to incorporate weights into my gym routine, I gained 5 pounds the first but then the second week I lost those 5 pounds plus 2 more. This isnt because I pushed myself or starved myself, it was just my muscles getting used to it. Also, remember...you continue to burn several hours AFTER lifting weights so it is so worth it.
Dont get frustrated...keep up the good work!