Charlie95, you mentioned that your girlfriend works abroad for a couple months at a time. I know very well how much being long distance puts a strain on a relationship - especially a relationship that also involves sex (I'm in a long distance relationship right now and I'm 20). I find myself overthinking at times and thinking of worst case scenarios that are mostly unfounded, and I have realized this is a product of missing my boyfriend a great amount... So in your case it could be also that you are overthinking because you miss her and wish she was around, it's up to you to ask yourself this question. I've had thoughts of how it would be to be with someone else when I have been really depressed. However, when I felt better about myself and had my normal amount of self-esteem I realized that I felt insecure about my boyfriend DUE to my depression stemming from other causes... Maybe it's something similar for you. You do sound like you have some feelings for this girl. Whether it's love or not is another question but I strongly believe that love takes time to develop. You have called her "amazing", "beautiful", "funny", "driven", and someone you can see spending your life with. She's helped you in the past with severe physical health issues and made a positive impact on your life. The fact that she's a couple of years older and more experienced with relationships shouldn't bring you down. Age differences in my opinion don't matter that much (especially ages that are as close together as yours and hers are). As for past relationships she's had, well, there's a reason she's done with them and with YOU now! There's this song I really like: "Listen to your heart, when he's calling for you... Listen to your heart, before you tell him goodbye" (well switch the him with her!) Good luck!