Need advice/vent

Do you ever feel like you just don't know how much more you can take? I'm 23 I have a 2 year old daughter and am currently 8 1/2 months pregnant with another little girl.i work as a supervisor for directv(I know they suck) been there 4 years and I love it! my kids have the Same boyfriend and I have been together for almost 4 years. I love him so much,but he does have ALOT of baggage he comes with...We lost a daughter at 20 weeks Dec of 2014 due to cord accident...the most worst experience of my life! I devoted to myself and God that if I conceived again I would make things right with certain lifestyle changes...well here we are and I really haven't held my end of the bargain,God blessed me and I haven't done anything different:( however the moral of this post is here lately I have been going through hell! I moved a "friend" in my home due to her and her little boy facing being homeless,she agreed to pay me 150$ a week which would include everything,rent,lights,cable,Internet,water even washer and dryer,she even used my detergent lol well she had an excuse each week and told me she would have my money feb 5th 300$ she owed me...well come feb 3rd while I'm at work I come home and ALL her stuff is moved out except for an old heavy box tv and trash:( and she had been smoking in the bathroom which I wasn't aware of cause she had her own bathroom and I never smelled it(no smoking in my house at all) Well I go to try to message her on Facebook and she has me blocked. I then txt her and she sends me a pic of over 1,000$ cash and says "f your money" so at that point I'm so mad! But being pregnant what can I boyfriend just informs me karma will catch her but dang,now I'm stuck cleaning her room negotiating with landlord to not put me out and being fully pregnant! The second scenrio my boyfriend and I got in a huge argument due to a girl on Facebook commenting heart faces on his pics,he swore to me that was his cousin,so I asked his sister and she said we are definitely not related to her,my boyfriend confessed and deleted her but he really mad a big deal out of it to the point we went to bed mad at each other over it...he swore this girl was his cousin! And told me to mind my  since I found the truth I've been pretty insecure and questioning a lot! And he gets mad and says I should trust him and she was never a threat..yet why did he lie? Aside from that I got him a job at Buffalo Wild Wings and ever since working there he's been kinda funny acting,I saw a girl outside and said she's pretty and he said she's 17,well I asked how he knew and he said he just can imagine how I was feeling then...but literally it's just been one thing after another...maybe I'm falling out of love with him and who he's becoming and how he treats me,cause in my mind I know my worth and It doesn't take a rocket scientist to go with a woman's intuition....advice anyone? Am I losing my mind?