Do I have anxiety?/ other problems?

I'm 18 In the morning I wake up feeling depressed I tend to always think back on the past previous days thinking about the bad stuff that happened to me never the good I am always think negatively about myself and what happens to me never the good (usually) during school I feel socially awkward sometimes I get tongue tied and my mouth gets very dry making it harder for me to speak around most girls which was never a problem for me until this year I used to be very outgoing. Occasionally ill have a week period or so were I am always swallowing and I cant stop until I stop thinking about it its not even swallowing spit its just to swallow and clear my throat? I think? Around friends I usually fake laugh because I find it hard to Truly laugh these days but guy friends are different because I can talk to them no problem then after school I smoke (weed) and if I'm with a group who is I know very well and smoke with all the time I am fine and I am outgoing but if its with people who are more popular then me I tend to get so nervous and I cant even Enjoy the high because I am so nervous which results in me hardly speaking, barely even being able to compile a thought, and feeling socially awkward, and when this happens I cant play sports which I'm usually good at or do much of anything not to mention my mouth gets really dry and that shuts me up even more. I also think very poorly of myself which I shouldn't since I know I am not as bad as I make myself feel but I some how convince myself that "I'm all that and more". I used to think very highly of myself and didn't care what others think but now that's all I ever think about. Can someone please help me out I don't know why that happens to me when I get high or why I always think so negatively or why I have become socially awkward around girls and in certain situations or why I cant really laugh anymore, and why sometimes I cant stop swallowing my mental state isn't great and I can really use some help....